Webhook for Deleting Multiple Attachment File

This thread discusses your issue.  It's probably by far the most efficient method in terms of the load on your app and the speed of execution.

https://community.quickbase.com/discussion/webhook-behavior-expected#bmf285a62c-005f-41b6-8e68-01872a7eefd2

BUT, I doubt that it can delete a file attachment using that method, so maybe the above is "just FYI" for a future use case.

So Plan B is to use a Pipeline for this as it will handle the multiple record changes.  

You can use the native Quickbase make Request Channel, and if you like use the shortcut format to just make a long URL.

Here is an example of running an API to Run a saved T2T import.  Just look at the help notes for API

https://mycompany.quickbase.com/db/xxxxxxx?a=API_RunImport&id=11

METHOD=POST

Or you can also use the similar syntax to the webhook but I think that the URL approach is simpler.

the URL syntax is likely

https://mycompany.quickbase.com/db/xxxxxxx?a=API_EditRecord&rid={{a.id}}&_fid_189=&filename=delete

Please post back and let us know if that works.