It really is a challenge for mobile lol, since you can't save you have to be critical lol
You can save by opening the save menu and pressing the little floppy disk icon or pressing the 'save to disk' button. It might look different depending on what browser setting or app you use, but surely you can figure it out. If you are using joiplay and it doesn't respond or something like that, check your permission settings for the joiplay app.