Hi @alexnemes, your approach looks good and worked for me with a little fine tuning:
Of course, I don’t have access to your authentication data or other nodes in your flow, so I used generic services working without authentication here. The file does, however, arrive as it should on the server and is readable:
As for the error you are getting, perhaps you can experiment with the HTTP Request response options a bit? Something like a “Text” response format should hopefully replace the decimal data with a human-readable error that might help with understanding what your server expects: