GNOME Keyring is a collection of components in GNOME that store secrets, passwords, keys, certificates and make them available to applications. It makes password storage secure and convenient. GNOME Keyring is integrated with the user's login, so that their secret storage can be unlocked when the user logins into their session. GNOME Keyring is based around a standard called PKCS#11, which is a standard way for applications to manage certificates and keys on smart cards or secure storage.
The alternative in KDE is called KWallet. However, they are designed with different standards and not compatible with each other.
Manage your keyring
The GNOME Passwords and Keys allows you to browse, edit and delete items in your Keyring.
This is also the best way to control the keyring username and password. See GNOME Passwords and Keys for more information.
A workaround is to use the Find Files/Folders utility to locate the Keyring folder on the machine. When located, proceed to delete all the files inside this folder. The next time the application is run and references the keyring, a prompt will issued requesting a new username and password. The newer versions allow a blank username and password, but discourage such practice for risk of breeching security.
Automatically unlock in SDDM+KDE
In GDM+GNOME, when you login, GNOME Keyring is automatically unlocked. However, it doesn't do so in SDDM+KDE. When you start some GNOME or Electron application, they ask you type login password again.
Here is a solution!
/etc/pam.d/sddm and add
#%PAM-1.0 auth include common-auth auth optional pam_gnome_keyring.so account include common-account password include common-password session required pam_loginuid.so session include common-session session optional pam_gnome_keyring.so auto_start
Then restart system.