Backend workflows: Missing parameter for workflow

Hi everyone. I’ve spent some time looking in the Bubble forums for similar posts, and the handful I’ve seen are either outdated or never received a reply. Hoping someone might have encountered this issue before and can point us in the right direction.

We’re trying to pass uploaded audio data to a backend workflow. We’ve configured the workflow to accept a parameter “audio” with type “file”, but continue to get error response codes:

{“statusCode”:400,“body”:{“status”:“MISSING_DATA”,“message”:“Missing parameter for workflow upload_wav: parameter audio”}}

We’ve confirmed in console logs that the audio is 1. not empty, and is 2. being sent correctly to the endpoint.

Thank you in advance for any pointers.