I don’t know my keychain password for my iMac

Hello jo jo 401k,

This page can help provide assistance for the keychain password on the Mac: If you need to update your keychain password on Mac - Apple Support

Your login keychain password is normally the same as your user password (the password you use to log in to the computer). At login, if your keychain password somehow differs from your user password, it doesn’t automatically unlock, and you’re asked to enter the keychain’s password. It’s recommended that you enter your previous user password. If this doesn’t unlock the keychain, the keychain automatically resets.

If you don’t remember your previous user password, you need to reset your default keychain. Resetting the default keychain deletes all the passwords saved in the keychain, but lets you sync your login password and the password stored in the keychain.

To do this, change your password in Users & Groups settings, and the keychain password is automatically changed to match it.

If your user password was reset because you forgot your password, and you can’t provide the old password for the keychain, you won’t be able to access the information in the old keychain, and a new blank keychain is created.

Cheers.

And next time write the password down and save it in a secure place for future reference.