System password manager?

I need some help understanding different kinds of passwordmanagers, I think.
I have Nextcloud Passwords and that works for passwords on websites.
I’m on Fedora KDE. I would also want that same passwordmanager, to manage the passwords on my system. Like, before I was on MacOS, altough I used BitWarden, I still had to use Macs Keychain for passwords in other apps then browsers.
That way it’s useless to use a NextCloud password-manager or BitWarden, since you still HAVE to use the other one as well.
Is it possible to use NextCloud Password-manager on your system or in a usefull way in colaboration with a system passwordmanager?

Not sure if that is what you’re looking for, but there is a desktop client for the Nextcloud Passwords app: Files · main · Matthias Fischer / Nextcloud Password Client · GitLab

Thank you bb77. I do have the application, that’s not the problem.
The problem is, that system-passwords are not saved by the application and the system seems only to work with the keychain program from the OS itself, KDE Wallet, for instance.