How to Control Parameters of Test Case in an execution Triggered from 3rd party System using Tosca REST API

Question

I have a business scenario wherein a user fills out a form in the 3rd party system with few parameters like "First Name", "Last Name", "Weight" etc.

Upon submission of form in the 3rd party system, a REST API call is made to Tosca, triggering one of the execution list.

The Test Case/Execution List in Tosca currently has the mentioned fields as Test Configuration Parameter(TCP), and the requirement is that the field values sent from 3rd party API should be utilized during the execution

I'm able to trigger the execution-list from 3rd party system, but am getting stuck on how to pass the incoming fields to the Tosca execution list during runtime

As per reply from Tosca Team, TCPs cannot be updated using REST API

Does anyone have any idea or experience of utilizing the values/variables sent from 3rd party system in their execution list using Tosca REST API. Any other workaround or feedback will be really appreciated

Thanks in Advance! :)