Importing a pre-existing save
Save data is located at "C:\Users\<UserName>\AppData\LocalLow\IronGate\Valheim\worlds"
Stop the server
Upload the .fwl and .db save files for the world you are wanting to play on to the "worlds_local" folder on the server using the file manager or FTP client
If the worlds_local folder is not present, you may need to create the folder first.
Edit the World Name option in your command line in the command line manager to use the same name of the world you were previously playing.
For example, if the world files were called dedicated.fwl and dedicated.db, you would set the world name to be dedicated