Autofill with Android OneUI Samsung s23 doesn't work

I answer myself: the solution is in this thread https://1password.community/discussion/126310/linked-apps.

Coming from lastpass, the application filled in the applis fields from the start because lastpass had a ready-made database.

But with 1password, you have to link item/app when you FIRST connect,

and then the link appears in the item as this:

What's not fluid for a user experience. We expect 1pwd to fill in the app fields straight away, and not that we have to open 1pwd > find the file > associate the file.
As FrankBreech says, "this extra set of 5 steps (click "search for entry", find the entry, click on the entry, then click "OK to use this entry") is a kind of a pain in the rear." !

What's missing is a warning AND the possibility, in the 1pwd app and windowsapp, of being able to link apps one by one in an interface, without having to disconnect from each one to be able to do so.
Because if you don't, the link can't be created.

And finally, it's not explained in the help page either... https://support.1password.com/android-autofill/ Too bad ;-) !