If you want to edit the RibbonX in your Excel workbooks on your Mac to make changes to your menu you must do that in Win Excel. But if you use a Dynamic menu you only have to add some RibbonX in your workbook one time and if you want to add buttons or want to change your menu you can do that in the VBE editor. So I hope the basic example workbooks that you can download below will help you understand how it is working. You can copy the sheets from your workbook in one of the files and you have a menu in your file without using a Windows machine to add the RibbonX.

If you are new to RibbonX you can start with this page to get more information :
Change the Ribbon in Mac Excel with RibbonX

Download example workbooks (File Dates 19-Aug-2023)

If you want to know the names of the images that you can use in the VBE editor for your buttons check out this page for a example workbook : Ribbon imageMso's in Mac Excel

The first example add a dynamic menu to the Home tab in a new group and when you click on it you see an English menu. If you want to change the menu you can do it all in the VBE editor.

The second example have the same menu but it check the Excel language and if it is Dutch you see the menu in Dutch end if it is German you see the menu in German. If it is not Dutch or German the menu will be English. If you look in the VBE editor you see that it is easy to add a language or change the menu.

The third workbook have an option to choose the language of the menu by changing the language dropdown.