I love excalidraw, but don't need the excalidraw+. But Excalidraw open source is the frontend only, which means I have to delete my drawings each time. So I built the backend so I can create many canvases.
Your site makes me make an account before I can use it, whereas excalidraw.com doesn't, and also excalidraw.com seems to save my drawing just fine? I closed a tab and reopened it and my drawing was still there, presumably from localStorage.
The three-lines-menu also has a "Save to..." option that lets you create a sharable link or save to your local disk.
I actually created a completely free chrome extension exactly for that reason helps you to save and open the files at excalidraw
https://github.com/AykutSarac/excalihub