Inject the test version of the hack at main menu
Press F1 to open menu
You'll see a friendlist box like in the main version of the hack
The friendlist box is bugged at the moment, it doesn't show you any names but I assure it still works.
You just have to click underneath the "friendlist" text to add players to yoru friendlist.
To check if you added the correct player to your friendlist, I suggest that you disable the feature: "Ignore Friendlies" under 3D options.
If you have that feature disabled the boxes of the players will go to pink, when they are pink then they are marked as friends.
Don't spam click underneath the "friendlist" text, just slowly click and see if it did anything, if not then go a bit lower and click again and so on.