Keychain Password

In the Keychain Access app. I would recommend that you begin by looking over and understanding Manage passwords using keychains on Mac

Yes, it should, but it is not for some reason. Most frustrating as it continues to ask for it every 20 seconds or so and truly interferes with enjoying my iMac. Tried rebooting in safe mode, worked in safe mode for a few minutes (awfully slow!) then rebooted, and lo and behold the beloved request pops up within seconds and over and over again.

Should be the same one you used to login to/startup your Mac…