This page offers a guide on how to complete Request 62: The Pokémon in the River Photo in Pokémon Legends: ARCEUS (PLA).
This request is given by Dagero, the owner of the photography studio. To have access to this request, you’ll first need to complete Dagero’s other requests, Request 25 and Request 44. Like all other Dagero requests, he’ll ask you to show him the Pokémon in his photo (see photo below).
Where to Find Turtwig in Arceus
The Pokémon in question is a Turtwig, and the photo hints that you can find one near water in Crimson Mirelands. More specifically, you can find a Turtwig next to the small pond across the river to the east of Ursa’s Ring. They’re pretty rare so you’ll want to be careful catching it - sneak through the long grass to get close enough.
Once you have a Turtwig at your disposal, head back to Dagero and show him it. You’ll unlock another new photography studio option!