The best way to execute operation from client on CRM

You have lots of restrictions i know. You are at client side and you can nothing about business logic. But ! Solution

Create dummy entity with your parameters

Create action

Code business logic under plugin

Create record in dummy entity

https://docs.microsoft.com/en-us/powerapps/developer/common-data-service/webapi/create-entity-web-api

call action

Call plugin from Javascript in Microsoft Dynamics CRM.

get your values

https://docs.microsoft.com/en-us/powerapps/developer/common-data-service/webapi/query-data-web-api

what a journey!