minecraft:on_prime triggers an event calls on an entity when the entity is set to explode.
Example
"minecraft:on_prime":{
}
Vanilla entities examples
tnt_minecart
"minecraft:on_prime": {
"remove": {
"component_groups": [
"minecraft:inactive"
]
},
"add": {
"component_groups": [
"minecraft:primed_tnt"
]
}
}