Add a password to a keychain on Mac
You can use Keychain Access to store passwords and login information for servers, email accounts, and other resources, so you don’t have to remember the information yourself or enter it when you log in.
In the Keychain Access app on your Mac, select a keychain in the Keychains list.
Choose File > New Password Item.
Tip: To add a new keychain item quickly, click the New Keychain Item button in the toolbar.
Enter the information for Keychain Item Name, Account Name and Password.
You can select Show Typing to show the characters as you type to make sure they’re correct.
Apps and servers may automatically create a keychain with a password for you when you create your account or login, or they may offer you the option to have Keychain Access remember the password.
Tip: To copy a password in a selected item quickly, choose Edit > Copy Password to Clipboard.