How to add multiple parts in multipart/form-data in an Azure Logic App

I am using Azure logic apps to send a file over HTTP using multipart/form-data. Unfortunately it isn't clear to me how to do the multipart of the request.

I have read the official documentation of microsoft on it. In their example they are only adding a file. I need to add some more parts to the form. In postman it looks like this:

When using a proper endpoint and proper key-value pairs for the form-data it works.

Sending the same request through the logic app doesn't work. I presume the body of my request doesn't look right. This is what it looks like now:

I would think that the body of the first part, so the part with name=file in the Content-Disposition of its header, should contain the actual content of the file.

I have come across the following answers to questions which are similar to mine but not exactly:

https://stackoverflow.com/a/59884777
https://stackoverflow.com/a/72138645

The first answer mentions that you can just add similar objects to the file object with correct form field names. However I can't seem to figure out what that would look like.

The second answer goes over adding one part to the form.

Any help on this topic would be greatly appreciated.

For anyone struggling with this, it seemed the body in my request was correct. I forgot to add the header

"Content-Type": "application/json"

to the first part. That is needed because I am sending a JSON file.