Insert an uploadedFile list inside a JSON

Hello, everyone! I am attempting to use a multipart API request to save some data to my custom backend. The goal I would like to achieve is to send a parameter, let's call it "parameter," as a JSON variable that would store a list of uploaded files and a string, similar to the following example:

{...

"parameter": {

"folderName": "",

"uploadedFiles": [list of uploaded files from the frontend]

}

}

I have tried to use custom functions to assemble my JSON before making the API call. However, every time I call my API, the request body contains an empty JSON {} as the value of my "parameter."

Has anyone encountered a similar issue or successfully achieved the desired results?

Thank you in advance,

C.D.