Hello @It,
Thank you for choosing XStore as your WooCommerce WordPress theme.
If you would like to add a custom link to the mobile menu, please first go to Dashboard -> Appearance -> Menus and create a custom link menu as per your requirements.
After that, please navigate to XStore > Theme Options > Header Builder > Mobile menu > and select the menu from the list of menus you have created in Dashboard -> Appearance -> Menus.
For further reference, please refer to the images provided at the following link: https://postimg.cc/QHGFjzTy and https://postimg.cc/N565Fx8f
Best Regards,
8Theme’s Team