Use the efa fabric setting
                update command to set or clear the MD5 password on a new
            fabric.
Here is the efa fabric setting
                    update command:
efa fabric setting update --name <fabric-name> --md5-password-enable <yes/no> --md5-password <password>
If the command is entered with md5-password-enable as “yes” but
                without the md5-password option, then a prompt is displayed to
                input string and the password string entered using the prompt is not displayed on
                the screen. 

Note
When providing a password string in the command line, that is usingefa fabric setting update --name <fabric-name> --md5-password
                        <password>, if the string contains special characters, then you
                    must enclose the string in single quotes. For example efa fabric setting
                        update --name fabric1 --md5-password ‘pass%!‘. Enclosing the
                    password string in single quotes is not required when the string is entered
                    using the prompt. After setting the md5-password, you must configure the fabric, using
                the command efa fabric configure --name <fabric-name>, to apply
                this MD5 password on fabric devices so that the BGP neighbor sessions are
                authenticated.
When you configure the md5-password on a fabric that has just been
                created, or a fabric that has not yet been configured, there is no change in the
                device app-state. However, if the md5-password is
                set after the fabric is configured, there is a new app-state, the
                fabric setting is refreshed (and devices will be set to), indicating the fabric
                properties have been modified and the fabric has to be reconfigured to apply the new
                settings. As part of fabric configuration, when the MD5 password was successfully
                configured on all the fabric links on a device, the app state on that device will go
                back to cfg-in-sync state.