This has been a long time coming. Sumur has up to now not really been playable on mobile using the HTML5/WASM version due to difficulties loggin in. I saw the potential solution for this issue in https://godotengine.org/article/godot-web-progress-report-7 a while back where the Godot team had added an experimental version of an on screen keyboard to Godot.
This was for Godot 3.3 and we are now at 3.5 and there is still quite some work to do on this feature. But it does work!. So from today you can play on your tablet or phone (I still havent made an automatic Android or iOS build so that will have to do for now).
Nice work Godot team.