Standard Notes can either use your operating system's password manager or its own local storage facility.
Standard Notes currently does not have access to your system password service. If you grant it access, you must quit the app for the change to come into effect.
Using local storage, your account keys may be more easily accessible by third-party programs, unlike in your password manager which has additional protections built-in.
In either cases, the strongest way to protect your account keys is to use a strong passcode, which will be used to encrypt your keys and prevent any software or operating system from reading them. If you plan on setting a passcode, you can safely use local storage.
Note that granting access to your system password service will allow Standard Notes to read, write, and delete any of your saved passwords. Standard Notes will never use this privilege to do anything more than reading and writing to its own entry.
Run the following command:
snap connect standard-notes:password-manager-service
Note: Password Service may also be referred to as keyring, saved passwords, stored passwords, password manager, passwords, or secrets, depending on your Linux configuration.