Dynamically set variables to invoke Decision API

Hi Team,
I have a use case to to invoke a DMN table which is deployed as a separate entity. When a user initiates a new process instance, I need to pass all the form variables as input to the decision API and invoke the deployed DMN and get decision out put based on the DMN rules. Basically this DMN performs some business validations based on the inputs.

How can I set dynamic variables and values while evaluating a decision.
Thanks in advance