API PDF from inbox to unexplained bank transaction

I used make.com to create a scenario where it sees emails in my inbox that contain invoice emails, scans for content, matches the details that it gets from freeagent on unexplained transactions and once matched, it picks up the attachment and it’s supposed to upload it. I tried different things /v4/attachments, now trying to make it work with /v2/bank_transaction_explanations but I am just going in the circles on the last step. A) I don’t have enough knowledge on this B) there’s limited documentation. I don’t even know if what I am trying to do is possible. I don’t know what format freeagent accepts. Need some help on this.

It’s definitely possible to upload an attachment to a bank transaction explanation. You need to update the explanation with the attachment data. See the attachment section of the attributes documentation.

The acceptable filetypes are PNGs, JPGs, GIFs, and PDFs (explained in the attributes documentation).