Is there a way to send data (customerID) from Looker Studio via webhook to Make?

I have another source of data to show in a Looker Studio report, but there is no pre-built connection between Looker Studio and the source. I can use Make to call the API, however I need the customerID.

The customerID can be set as a constant in the Looker Studio report.

The difficulty I have is sending the customerID out of Looker Studio.

I've been able to connect Looker Studio and Make to return the correct information and display it, however I set the customerID in Make. Which is not a reusable solution.

Is there any way to develop a webhook payload from Looker Studio. I've been told it is not possible send any data out of Looker Studio.

Here is a video showing what I have tried: ;share=copy