Adding maps to your TF2 servers map rotation is fairly straightforward and easy to accomplish.
If you already have a custom map you want to add to the map rotation of the server. If not, refer to the guide Using Custom Workshop Maps then continue with this guide.
- Head into your TF2 server gamepanel and navigate into 'Configuration Files'.
- Open the config file 'maprotation.txt' using the text editor.
- Paste in the map you wait to use and then save and start your server.
Maps can be found in the file manager in the game panel, Open the File Manager then go to the folders tf\maps\ then copy the name of the map you want to use and paste it in the maprotation.txt file: arena_badlands.bsp minus the .bsp.
So you list then looks like this: