How to connect my GCP Project from Zenphi Workflow using http call

We have created a Processor on Doc AI of Google. This has better extraction of documents & as per our requirement. Now we want to use the same processor (created on GCP) within Zenphi flow. Rest all steps will be same as before.

We have referred to this - https://docs.zenphi.com/docs/http-call

This is not taking the GCP URL of our processor, not sure what we are missing?

Can you share a detailed steps for above.? a video explanation is better.