1. On Marketing > Menu Builder click + New Menu Group.
2. In the Add New Menu Group dialog enter a Title (for example "Main Header Navigation") and choose Menu Position: Header or Footer.
3. Click Save Menu Group. The group appears in the table (inactive) for the current kitchen.

A blank title is rejected ("Title Field is Empty"). Next, click the group name to open the builder and add links, then switch its Active toggle on when you are ready.