Can't upload a file to HubSpot using Retool<->HubSpot API

Hi there,

I'm nearly at the end of my tether! I can't upload a file (binary data) to HubSpot - and I can't find any help online that fixes the issue. I've tried various different attempts, but can't solve it.

This is the response I'm getting:

Any help appreciated!

I'm assuming the file data is all good, as I can save the file from the "GetPDF" query to a file via the utils.downloadFile function - and the file looks good.