How do I make players kill a required amount of zombies b4 it stops spawning

[ebon canopy]

I'm making a game somewhat like left 4 dead

u basically kill around the map finding shit

[stable tangle]

you set a variable named "killed"

everytime the player kills a zombie

you register that kill

also maybe verify it

check if there are no exploits involved

then update the killed variable to be one more than it was before

if now that "killed" variable is >= then required kills,

you stop spawning

the zombies

and thats it