as an alternative you can do what I did and make a shortcut with the following target:
"C:\Program Files (x86)\Blockland\BlocklandLauncher.exe" -dedicated -map SPAAAAAAACE
I found this useful because for some reason .bat files give me weird permission requests sometimes, and I don't think they will be able to run at all if you are on a school computer with those kinds of restrictions. A shortcut should still do the trick, however.