I see! So probably 2 issues. The first is that I screwed up the instructions! Its actually spacebar to dash and I wrote Shift. 🤦♂️ The map issue might be related to the keyboard you are using. I used physical keys in the Godot settings, so for me the M key is basically the most bottom right letter. For you this might be a different key. I made the mistake of not using physical keys in one of my games and it made using WASD a nightmare for people with certain keyboard setups.
Sorry for the subpar experience! Key bindings has been on the list of things I always want to do, but run out of time for.