I'm trying to make an add on to the Mod CP, but as I look into the controller, it checks to see if there is a class in the extensions folder.

For example: modcp/reports goes to \IPS\core\extensions\ModCp\Reports. So if I had modcp/test it would look for \IPS\core\extensions\ModCp\Test, which you can't make with a plugin.

I already got the link made, now where should I make the method?

Unfortunately, you need to either (1) write an application to accomplish this (it doesn't need to be in the core application's folder), or (2) instruct the user to upload the file to an existing application's folder.

We are discussing ways of expanding the plugin system in the future to accommodate things like this better, but as of right now those are your only real options.

I made ~ 1 year ago.