Palworld gameplay settings — such as XP rate, difficulty, and drop rates — are stored in the PalWorldSettings.ini file, inside the OptionSettings=(...) line. You can edit it from the Files page.
Always edit this file while the server is stopped:
Open the Console page and Stop the server.
Open the Files page and edit Pal/Saved/Config/LinuxServer/PalWorldSettings.ini.
Change the values you need inside the OptionSettings=(...) line, keeping the existing keys and formatting intact.
Save the file, then Start the server.
Important: A running server rewrites this file when it shuts down, so changes made while it is running are lost. Keep every key inside OptionSettings=(...) correctly formatted — if the format is broken, the server resets the file to defaults on the next start.
If you need help with this, please submit a ticket.