Trainer Condition won't play specified battle music

[LifeOfBlu]

Description

Trying to make a resource pack that will play different music when battling trainers as opposed to wild pokemon.

How to reproduce

I've set my json file up as follows

{
"type": "battle_music",
"conditions": [
{
"type": "trainer"
}
],
"music": {
"start": "",
"loop": "pixeltweaks:trainer/loop",
"end": ""
},
"priority": 20
}

Context

Pixelmon Version: Pixelmon-1.16.5-9.1.12-universal
PixelTweaks Version: PixelTweaks-Client-1.10.6a
Server or Single Player: Singleplayer