If you already have an automated message set up to send lock codes, in order to share the new Guesty Locks Manager guest codes you must update the variable from {{keycode}} to {{guest_access_code}}.
The "Keycode" field and {{keycode}} variable still exist in Guesty for codes created for guests by partners. The new "Guest Code" field and {{guest_access_code}} variable are specific to Guesty Locks Manager and should now be used in your automated messages.
See more information here.