`
#Make a scoreboard:
/scoreboard objectives add Count dummy
#Add 1 to a FakePlayer for every player:
#RUAA0:
execute as @a run scoreboard players add Players Count 1
#Run command based off player count:
#CUAA0:
execute if score Players Count matches <int> run <command>
#Reset count:
#CUAA0:
scoreboard players reset Players Count`