Edit a custom field with JSON on workflow post funciton

Hi all

I really hope someone can help me here :slight_smile: I have custom field that is created and populated using a custom connect app.

I want to set a value on that single select field using a post function in a workflow transition - I have an automation rule that does this but want to get right of the automation rule. I have the below post function but it does not set the value option value to the single select field Application … (I also do not want to make it a default field value)


Please advise?

Thank you in advance