1)Â Navigate to the Commandline Manager > Custom Commandlines and create a new custom commandline.
2) In the Custom Commandlines, you will see "LevelURL" parameter. Make sure to tick the box to the left of it and insert the following:Â
https://www.dropbox.com/s/SomeRandomCharacters/YOUR_FILE.map?dl=1
Replace the URL within the quotation marks to your link with the downloadable .map file.
NOTE: If you are using Dropbox, then please make sure after the .map that there is ?dl=1 as shown above.
3) Save and Select the Custom Commandline. By default your server should restart.