Sapper/svelte blog on a firebase database not working as intended

I’ve build a blog based on this tutorial and it seems to be working fine but there are some strange things that were working on my local server and doesn’t work now. For exemple when you get on a project article, normally if you add /edit at the end of the url, it opens an edit page, but on netfly it doesn’t. When I want to create an article, it opens the page but when you put the password and click on save, it doesn’t work.
the URL : koebelt.netlify.app

Netlify needs an index.html at each path it serves. Without it, you’d get a 404. I guess you can try something with redirects, but I’m not sure it will work.