Change Game Settings for Valheim

Before the first server start

It is easiest to adjust the settings before the server is started for the first time.
Create a new server for Valheim by clicking on Add game or + in your server overview on 4Netplayers.com.
Make your desired settings and complete the creation.
If you are asked whether you want to start the server, click on Cancel.
Under Server settings you can select a preset under Preset.
Under Server Settings -> Customisation Settings you can further customise the preset according to your preferences.
When you are finished with your settings, click on Save and start the server.

Info: If you add the server as a favourite ingame, you may not see the changed preset,
nor the adjustments you have made.

After the first server start

Unfortunately, the settings for presets and other customisations can no longer be changed via the server after the first start.
Download your savegame as described here: download savegame
Then copy this to your local save directory and start your game.
Now load the server savegame. As soon as it has been loaded, you can change all settings ingame.
When the game has saved, quit the game again.
Now upload your savegame again as described here: upload savegame
Start your server. If everything went well, the new settings are now active.