This advancement can be earned regardless of how the fire was prevented. Lightning can strike anywhere, but there are many blocks which cannot be lit. For example, if a Channeling trident is thrown at a villager in a snowy biome, snow won't light on fire. As long as there are any other villagers within range, you will be granted the advancement. The same can likely be said of any other partial surface such as slabs and in water.
I've also found that if a monster is trapped on lit netherrack, such as a zombified piglin, the advancement will be granted. Likely because the lightning doesn't place new fire if there is already an existing fire, and that counts.
Annarkwin
This advancement can be earned regardless of how the fire was prevented. Lightning can strike anywhere, but there are many blocks which cannot be lit. For example, if a Channeling trident is thrown at a villager in a snowy biome, snow won't light on fire. As long as there are any other villagers within range, you will be granted the advancement. The same can likely be said of any other partial surface such as slabs and in water.
I've also found that if a monster is trapped on lit netherrack, such as a zombified piglin, the advancement will be granted. Likely because the lightning doesn't place new fire if there is already an existing fire, and that counts.