This command toggles flight mode.
The fly
command in Valheim is a console cheat that allows you to fly through the game world. This enables you to navigate the extensive maps much faster and bypass the various dangers that come with traveling through the land or sea, such as enemies or difficult terrains.
It's especially handy for exploration, uncovering areas in the map quickly, scouting for potential base locations, observing enemy camps and structures, or even escaping from a difficult combat situation instantly.
The fly
command it turns on or off the ability for the player to fly in the game.
This can enable the players to traverse the game environment quickly without any obstacles such as terrain or enemy mobs.