READ THIS BEFORE !
HERE IS THE GUIDE TO KNOW THE DIFFERENCE WITH THE TWO FORTNTIE ANTICHEATS: BE AND EAC!
Only play with Battle Eye
EAC = Easy anti cheat
BE = Battle Eyes
BE and EAC are two Fortnite anti-cheat and their operation is very simple, but first we will learn to differentiate them.
If your account is on EAC, you will have this image when you start the game.

Or alternatively, once your game is launched, open your task manager and look for a process like this.
And if you notice that it says Battle Eyes instead of "Easy anti cheat", that means your account is on BE.
Each day, your account is associated with one of these two anti cheats (EAC or BE) and will form a cycle like this.
ACCOUNT : Day 1 / EAC | Day 2 / BE | Day 3 / EAC
If you are looking to play on the least secure anticheat you can use this pattern which uses 2 accounts.
1 ACCOUNT : Day 1 / EAC | Day 2 / BE | Day 3 / EAC
2 ACCOUNT : Day 1 / BE | Day 2 / EAC | Day 3 / BE