Lock or unlock your keychain
Your default keychain, which is created for you when you set up macOS, is unlocked automatically when you log in or when you enter your keychain password in an Unlock Keychain dialog. Your keychain password is always the same as your login password unless you used Keychain Access to create a different password, or if you used Keychain Access to change the password of an existing keychain.
You can set your login keychain settings to automatically lock after a designated number of minutes of inactivity or when your Mac is in sleep. See Set how often you’re required to enter your keychain password.
Open the Keychain Access app on your Mac.
If keychains are not visible in the left column, choose View > Show Keychains.
Select a keychain in the Keychains list, then click the lock icon at the top of the window to lock or unlock the keychain.
If a dialog asks you for a password, enter your keychain password.
You can display a keychain lock icon in the menu bar and use it to quickly lock or unlock your keychain. In Keychain Access, choose Keychain Access > Preferences. Click General, then click “Show keychain status in menu bar.”