PS C:\Users\*name*> cd C:\valheimserver\
PS C:\valheimserver> umod install valheim -P
[uMod] 09:30 AM [Warning] No game installation found. Use "umod install --help" to install a game server.
[uMod] 09:30 AM [Warning] Unable to find game
No game installation found
I just ran into the same issue. replying to see update. I haven't had any luck myself atm.
D:\Program Files (x86)\Steam\steamapps\common\Valheim dedicated server>umod install valheim -P
[uMod] 09:15 PM [Warning] No game installation found. Use "umod install --help" to install a game server.
[uMod] 09:15 PM [Warning] Unable to find game