Error when starting a process from a write record API, "Record Type can only be indexed into using square brackets or the index function"

I have a Write Record WebAPI that needs to start a process. The purpose of the process is to notify a user group that a new speaker request has been added to the system.  I keep getting an error when trying to kick off the process, "PMSO Volunteer Request can only be indexed into using square brackets or the index function"

I created a blank process (start node and end node) called "PMSO New Speaker Request".  There is one process variable created "entryId" that is set to be a parameter.

The Web API

a!localVariables(
  local!value: cast(
    'recordType!{ca4c278b-1034-49bc-af7d-e4c16cf132b6}PMSO Volunteer Request',
    a!fromJson(http!request.body)
  ),
  a!writeRecords(
    records: local!value,
    /*
    * Construct an HTTP response to return to the caller
    */
    onSuccess: {a!httpResponse(
      statusCode: 200,
      /*
      * Set an HTTP header that tells the client that the body of the response will be in JSON format
      */
      headers: {
        a!httpHeader(name: "Content-Type", value: "application/json")
      },
      /*
      *In the response body, return the records created or updated
      */
      body: a!toJson(fv!recordsUpdated)
    ),
    a!startProcess(
      processModel: cons!PMSO_NewSpeakerRequest,
      processParameters: {
        entryid: local!value.entryId
      }
    )
    },
    onError: a!httpResponse(
      statusCode: 500,
      headers: {
        a!httpHeader(name: "Content-Type", value: "application/json")
      },
      body: a!toJson(
        a!map(
          message: "Write request has failed",
          error: fv!error
        )
      )
    )
  )
)

Data is posted to the Record Type, PMSO Volunteer Request, but the process is not started.