API sending PDF issue

I’m trying to send a PDF via the API Connecter. All the API calls to the other app work, only sending the PDF isn’t. I did it via Postman and it worked fine, with the same settings.
According the other side, the issue is:
" Bubble API probably aren’t processing files bytes like postman did. Our api endpoint is expecting the file bytes should start with this format “%PDF” or “<?xml” "
Could anyone tell me what I should change here? Below is the screenshot of the API Request:

I would guess it’s about sending the file as a file. Any reason you can’t send the S3 url for the file?

In Postman are you sending the file as form-data, or are you sending it as binary data like this?

And make sure all your headers are the same, even check the default/hidden ones Postman adds and see if any of those need to be added to Bubble.

If its form-data you probably have it correct in Bubble, but binary data is more tricky and not do-able w/ the API Connector

It’s indeed binary.
So is there any solution for this outside of the API connector?
As I’m afraid I cannot change it at the receiving side (an external provider)