Hm, does not work on my Linux machine. The hand icon appears, and if I press the trackpad button it clenches, but the canvas doesn't actually move.
Fedora 44 with Gnome 50 on a Framework 12 laptop.
I figured out the problem though. I had the "disable touchpad while typing" setting toggled, and of course, it registers the holding-down of spacebar as "typing" and dutifully disables the touchpad. If I untoggle that setting, it works.
Might be worth finding a way around it. I imagine that's a popular setting to have activated.