This page offers a guide on how to complete Request 46: Setting Up the Coastlands Camp in Pokémon Legends: ARCEUS (PLA).
This quest is picked up from Gully, who’s found east of Aipom Hill in Cobalt Coastlands. She’ll ask you to help find Yorrich who has gone missing.
Where to Find Yorrich
Even with this request activated in the requests tab, you won’t actually get told where to find him via a marker. If you open up your map, you can see that the Sand’s Beach penninsula resembles a hand - Yorrich is found on the rightmost “finger” (see map below).
When you speak to Yorrich, you’ll find him being terrorised by a level 34 Chatot. You’ll probably have no trouble defeating it, but if you’re worried just bring out a Pokémon that knows Rock, Electric and/or Ice-type moves to deal extra damage towards it!
Once you’ve helped Yorrich, he’ll set up the Coastlands Camp and you’ll now be able to fast travel to the new camp, switch out your Pokémon or rest there to recover!