What is the best way to approach for this requirement

a!localVariables(
  local!data:ri!asr_Requests,
  local!rawEmails: ri!asr_Requests.emailAddresses,
  
  local!integrationResult,
  local!isintegrationSuccess,

  local!individualEmails: reject(
    a!isNullOrEmpty(_),
    a!forEach(
      items: split(local!rawEmails, char(10)),
      expression: trim(fv!item)
    )
  ),

  local!invalidEmails: reject(
    a!isNullOrEmpty(_),
    a!forEach(
      items: local!individualEmails,
      expression: if(
        regexmatch(
          pattern: "^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,}$",
          searchString: fv!item,
          regexFlags: "si"
        ),
        null,
        fv!item
      )
    )
  ),

  /*local!formattedEmailString: joinarray(local!individualEmails, ","),*/

  local!formattedEmailString: a!toJson(
    {
      emails: joinarray(local!individualEmails, ",")
    }
  ),
  
  local!validationMessage: if(
    a!isNotNullOrEmpty(local!invalidEmails),
    "Emails must be valid and each on a new line.",
    {}
  ),
  a!formLayout(
    label: "Production Validation Request",
    contents: {
      a!sectionLayout(
        contents: {
          a!columnsLayout(
            columns: {
              a!columnLayout(
                contents: {
                  a!boxLayout(
                    label: "",
                    labelSize: "SMALL",
                    contents: {
                      a!columnsLayout(
                        columns: {
                          a!columnLayout(
                            contents: {
                              a!textField(
                                label: "Title:",
                                labelPosition: "JUSTIFIED",
                                value: local!data.requestTitle,
                                saveInto: {
                                  a!save(local!data.requestTitle, save!value),
                                  a!save(
                                    ri!asr_Requests.requestTitle,
                                    save!value
                                  )
                                },
                                refreshAfter: "KEYPRESS",
                                characterLimit: 100,
                                required: true,
                                requiredMessage: "Title is Required"
                              ),

                              a!dateField(
                                label: "Start Date",
                                labelPosition: "JUSTIFIED",
                                value: local!data.startDate,
                                saveInto: {
                                  a!save(local!data.startDate, save!value),
                                  a!save(ri!asr_Requests.startDate, save!value)
                                },
                                required: true,
                                requiredMessage: "Start Date is Required",
                                validations: rule!asr_startDateValidation(ri!asr_Requests.startDate)
                              ),

                              a!dateField(
                                label: "End Date",
                                labelPosition: "JUSTIFIED",
                                value: ri!asr_Requests.endDate,
                                saveInto: {
                                  a!save(local!data.endDate, save!value),
                                  a!save(ri!asr_Requests.endDate, save!value)
                                },
                                required: true,
                                requiredMessage: "End Date is Required",
                                validations: rule!asr_endDateValidation(
                                  ri!asr_Requests.startDate,
                                  ri!asr_Requests.endDate
                                )
                              )

                            }
                          ),
                          a!columnLayout(
                            contents: {
                              a!textField(
                                label: "Requested By:",
                                labelPosition: "JUSTIFIED",
                                value: rule!GBL_displayUserFirstLast(loggedInUser()),
                                saveInto: ri!asr_Requests.requestorName,
                                readOnly: true()
                              ),
                              a!textField(
                                label: "Requestor Email:",
                                labelPosition: "JUSTIFIED",
                                value: loggedInUser(),
                                saveInto: ri!asr_Requests.requestorEmail,
                                readOnly: true(),
                                validations: {}
                              ),
                              a!dateTimeField(
                                label: "Requested On:",
                                labelPosition: "JUSTIFIED",
                                value: now(),
                                saveInto:  ri!asr_Requests.createdOn, 
                                readOnly: true(),
                                validations: {}
                              )
                            }
                          )
                        }
                      ),
                      a!paragraphField(
                        label: "Email Addresses",
                        labelPosition: "JUSTIFIED",
                        placeholder: "Email Addresses should be one per line (can be pasted from Excel)",
                        value: local!data.emailAddresses,
                        saveInto: {  
                          /*a!save(*/
                            /*local!integrationResult, rule!asr_bulkgetemployees({local!formattedEmailString}),*/
                          /*),*/
                          a!save(local!data.emailAddresses, save!value),
                          a!save( ri!asr_Requests.emailAddresses, save!value)
                        },
                        refreshAfter: "KEYPRESS",
                        height: "TALL",
                        required: true,
                        requiredMessage: "Email Address is Required",
                        validations:if(
                          (a!isNotNullOrEmpty(local!invalidEmails)),
                          "Emails must be in a valid format, and each email must be on a new line. ",
                          {}
                        )
                      )

                    },
                    style: "#134f5c",
                    marginBelow: "STANDARD"
                  )
                }
              )
            }
          )
        }
      )
    },
    buttons: a!buttonLayout(
      primaryButtons: {
        a!buttonWidget_23r3(
          label: "Submit",
          style: "PRIMARY",
          submit: true,
          validate: true(),
          saveInto: {
            a!startProcess(
              processmodel:cons!asr_WRITE_REQUESTS,
              processParameters: {
                Emails:local!formattedEmailString
              },
              /*onSuccess:a!save(local!processId,fv!processInfo.pp.id)             */
            ),
            a!save(
              ri!asr_Requests.requestorName,
              rule!GBL_displayUserFirstLast(loggedInUser())
            ),
            a!save(
              ri!asr_Requests.requestorEmail,
              loggedInUser()
            ),
            a!save(ri!asr_Requests.createdOn, now()),
            a!save(
              ri!asr_Requests.requestStatus,
              cons!asr_AUDIT_STATUS_TYPES[1]
            ),
            a!save(
              ri!asr_Requests.requestType,
              cons!asr_REQUEST_TYPE
            ),
            a!save(ri!asr_Requests.isActive, true())

          },
          loadingIndicator: true()
        )
      },
      secondaryButtons: {
        a!buttonWidget_23r3(
          label: "Cancel",
          style: "NORMAL",
          submit: true,
          validate: false,
          value: true,
          saveInto: ri!cancel
        )
      }
    )
  )
)

This is my interface .Will enter emailaddresses in line by line format and it should validate the emailaddress format .Once it is done when we click on submit it should pass all the FormattedEmailAddresses to the integration .The input of integration should be emailaddresses and the output of the integration is GUIDs which is an array .