How to send user file to update already compiled game?

Hi, new user/not a coder...

I am working on a game where all data is saved to playerprefs and this is working OK. When released I want to have a few packages available..

One will be the trials, no save functions. If you want to "register" you log into the website and download a "config" file which would set the username/setup. As you play/advance this info is uploaded to the server (this is working OK too) sand you would be able to then download this file (if you ever lost/changed devices).

I see some examples of how to write to playerprefs but am unsure of the filetype to create/use.

Unitypackage would be my guess never done this so any direction appreciated.

thanks!