If you can’t find any options inside of the property-panel, then you maybe have another option to do it programmaticlly.
The menu provides API to be able to set and to get MENU-ITEMS as OBJECT. Take a look into the corresponding provided CODE-OPTIONS, here…
https://www.wix.com/velo/reference/$w/menu/introduction
Read the INTRODUCTION, try to understand it and then do what you want programmatically.
BTW: This one is new???
https://www.wix.com/velo/reference/$w/menu/menuitems
Never payed attention onto it. Nice to have.