You could try finding where the map is stored on your PC and upload it on google drive or something. Then have your friend delete his original copy of the map and have him move yours in. Idk if it will work but thats worth a shot. Or just start over its a rogue like and not a big deal anyways but that depends on your patience for that.

In CSGO's local files folder under csgo/cfg there are rogue_savefile_*.log files, I'm not sure if both the settings and the slot file are needed, but sharing them together definitely works.