In most applications, the F6 keyboard shortcut is used to focus the url/search bar.
For instance in Firefox, Chromium for the url, and in Dolphin for the file path bar.

Since the search bar situated at the top of the application is the starting point when using KeepassXC, it would be great to be able to keep the same shortcuts that we are used to, by adding F6.

It seems the subject is a bit touchy, so adding instead of replacing the existing F3 could be the way to go.

Better yet, let the users configure the shortcut themselves, in the kde-way :)