Odoo Quick Tips - Form Actions [Website]

In v13 we had a custom web form for a custom made database (with studio) .
Now we switch to the v16 (saddly) and it isn't working (like many things what we made with studio) and i can't select the my database where i want to save the datas...

So I need to make the whole database and web form again?

If yes, it is very confusing to make again all of custom modifications on every update... :/

Ripping off my nails with a plyer would have been more productive than this video.