Download the loader here: https://cdn.smgcheats.com/client

Make sure you have uninstalled all antivirus programs (Avast/Eset/Kaspersky, etc.) and not just disabled them.
Uninstall Faceit/Vanguard anti-cheats and disable all Windows protection.

Run the loader
Enter the key
Click "Inject."
If you are blocked in the game, you should only press "Yes" to the first question (always, until you restart your computer) and "Yes" to the second question (once after each block).
Wait for the message that the cheat has been loaded and then enter the game.
Open Scum, load to the main menu, and press F2. There will be several delays.
HOME/Insert menu

WARNING! Before launching other games after playing with the cheat, restart your computer.