What's the correct way of reading this endpoint? - php

Question

I got an API endpoint that I need work with that looks like something below (it's a POST request) which revolves around uploading images to a server.
Does the parameters: part mean that the URL should be populated with whatever the user has uploaded upon form submission (upon clicking submit)? For example: www.website.com/upload_identifier=398/File=abc12 ? where upload_indentifier & File are user driven and that it needs to reflect in the URL? I think not because GET requests populate URL rather than POST requests.
I just want to know if I'm reading this correctly before diving in. Thanks for reading.
parameters:
- upload_identifier
- File
Response code: 200 - success
{
"isValid": true,
"message": "Succuesfully complete request",
}
Response code: 200 - error
{
"isValid": false,
"message": "Access Denied. Invalid Credentials. Contact your administrator",
"code": "0",
"message": "Access denied",
"message": "Access denied",
}
Response code: 400 - error
{
"isValid": false,
"message": "Invalid file type" / "File too large",
"code": "5",
"message": "Error in expected params",
"message": "There are missing or invalid parameters than expected"
}
Response: 400 - error
{
"isValid": false,
"message": "Request already processed",
"code": "6",
"message": "Record already exists",
"message": "Record already exists"
}