Dagero asks you to identify the pokémon in the nighttime photo and show him one.

The Request

If you have completed The Pokémon in the Woodland Photo and completed enough missions, you can talk to Dagero in Jubilife Village to accept this request.

Catch the Pokémon

The pokémon in the photo is a Duskull. They can be found in Deadwood Haunt in the Cobalt Coastlands, only at night.

Reward

After you catch a Duskull, show it to Dagero. This will unlock a new option in the Photography Studio.