Help me troubleshoot an error uploading a file to Amazon S3 with React as front-end

I'm attempting to create an upload feature in my app that uploads audio files to an Amazon S3 bucket. When I use my API gateway link to generate an upload url, and then do a POST request with Postman with a file, this is the result.

https://gist.github.com/TheNomadicAspie/dd6d9542af41ff3983a3f2854a343225

If you can help me fix the issue so I can get a basic file upload feature working in my React app, please bid the amount you can complete the project for and include the word "rubber duck" so I know you've read the description.