No you put the ROSTER-LionsGoBlue file in your Documents\Madden NFL 20\settings folder.
Then you launch the game with the mod enabled, you will see a special splash screen with Tom Brady in his Michigan uniform number 10 that way you know the mod launched ok.
Once in game you need to go to the area where you save/load files and load the LionsGoBlue roster that should now show up on your roster list if you copied it to the right place.