How to pass multiple input parameters to Process Model exposed as webservice in

Here is the usecase,
We have an external (not an Appian) application on which form with 3 different fields would be submitted by user and we need to pass these 3 fields values to invoke a process in Appian.

What you recommende for this ? Webservice as a process model with ability to accept multiple input parameters ? How to do that ?

Here is the usecase,
We have an external (not an Appian) application on which form with 3 different fields would be submitted by user and we need to pass these 3 fields values to invoke a process in Appian.

What you recommende for this ? Webservice as a process model with ability to accept multiple input parameters ? How to do that ?