Spawning pattern: spawn 2 when one killed

Hi! Thank you for your answer.
Your answer works very well. However, I wanted to benefit from my spawner settings about Randomization. I managed to do that programatically:

When a zombie dies, I get my only spawner in the scene, and I make 2 zombies spawn from this spawner. The code is very easy:

//Inside zombie death method
WaveSyncroPrefabSpawner spawner = LevelSettings.SyncroSpawners[0];
spawner.SpawnOneItem();
spawner.SpawnOneItem();

This code works with my current settings, but I don't know how well this can be adapted for multiple spawners.

Jery