Deployment Azure function from Business Central

I attempt to deploy an Azure function utilizing Rest API and a solution zip archive.

It functions correctly in Postman.

I have discovered how to upload mp3 files and developed a solution for my assignment.

But when I attempt to generate a payload for an AL-code request in Business Central (the file has been uploaded to the instruction):

I received an error in the response message from the deployment process like this:

I believe, something is wrong when I build the payload. Could you give me advice on how I have to build the body of request for my case?