Send submission to MySQL database using PHP: any idea how I could get the field name?

Hello.

I'm in the process of connecting a form made with jotform to my SQL database
The issue I'm having is that the section that is receiving the mp3/wav file uploads on jotform has no visible field name, and so I can't pass the required file to my database (through $_POST).
Any idea how I could get the field name? I've searched in the advanced area and can't seem to find any option to grab the field name.
Below is a picture that can help explain the problem.

Thank you for the attention :)

What is your form in question? In order to find them easily, enable the "Send Post Data" setting in your form:

Then put the following URL in your Thank You page: https://www.jotform.com/show-post-data/

Finally, do a real submission in your form in order to see the PHP code, example:

Result:

Let us know if you need more help.

Thank you for your help.