Making a Post API to PhotoRoom to remove image backround

Hi All

Am wondering if anyone can help me integrate the PhotoRoom API with Airtable.

The API removes the backround from an image.

I am running into roadblocks, and get the following returned:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
400 Bad Request

Bad Request

Could not decode image, ensure image_file or image_file_b64 is set

I am very, very new to scripting, and this is probably quite a straightforward task for an experienced coder / scripter!!

Any guidance as to how to do this would be greatly appreciated.

Thanks
Jamie