кароче 1.21.4+
создаёшь скорбоард /scoreboard objectives add damage minecraft.custom:minecraft.damage_taken
дальше порядок снизу вверх
/scoreboard players set @a[team=players,scores={damage=1..}] damage 0
/execute as @a[team=players,scores={damage=1..}] if score @s damage matches 1.. run твоя команда