Depends on what your using/how its set up.

GNOMEs native password manager "Passwords and Keys" has the opportunity to store the Browsers Keyring. So if you store passwords in Firefox/Chrome they get stored in Passwords and Keys (and then auto gilled in the browser).

KeePassXC has a Browser plugin, as long a your password databases is unlocked it will autofill inside the Browser.

Its Linux, so there is not one solution and it won't simply work across all apps.