Minecraft 1.16.5 | ~onExplode doesn't work.

Minecraft Spigot 1.16.5 I want to put a skill that plays when a creeper explodes, but it doesn't work. The skill is:

CreeperExplode: Skills:

• effect:particlesphere{particle=flame;amount=20;radius=1} @self
• ignite{ticks=600} @PlayersInRadius{radius=1}
• delay 3
• effect:particlesphere{particle=flame;amount=20;radius=1.5} @self
• ignite{ticks=600} @PlayersInRadius{radius=1.5}
• delay 3
• effect:particlesphere{particle=flame;amount=20;radius=2} @self
• ignite{ticks=600} @PlayersInRadius{radius=2}
• delay 3
• effect:particlesphere{particle=flame;amount=20;radius=2.5} @self
• ignite{ticks=600} @PlayersInRadius{radius=2.5}
• delay 3
• effect:particlesphere{particle=flame;amount=20;radius=3} @self
• ignite{ticks=600} @PlayersInRadius{radius=3}

In the mobs file, the skill is represented like this:

• skill{s=CreeperExplode} @self ~onExplode 1

I have tried change @self by @origin and even @selflocation in both files but it doesn't work. Any Ideas?