How do i make the enemy respawn

I need help make ing this i need to learn how to make enemys respawn after i kill them all here is the game its kinda like space rangers.

When the enemy’s killed, send a message to the spawner telling it to spawn another one.

or just when it is killed start a timer that at the end it emits another enemy

U already said something to this effect, if you had it emit from for example a nearby block when the game starts, and then when you kill it the block emits another one? This isn’t tested and I’m not sure it would work but u could try.