The number of wholesale menus per kitchen is capped by an internal limit called Max Number of Wholesale Menu (default 1) that is not exposed in your own Configurations pages — only Sprwt staff can change it, which is why the warning tells you to contact Sprwt rather than pointing you to a settings page. When the count of existing menus reaches the cap the + Add menu button is hidden and a warning reads You have only N active wholesale menu available. To get more please contact Sprwt. Because menus cannot be deleted in the current version, ask Sprwt to raise the limit or reuse an existing menu (you can rename it inline by clicking its name).