We have several stores and a store view. We configured as your user guide but the flags don't display in the frontend.
Can you please suggest a way forward to display the flags for existing stores?
The module Magento 2 Store View Flag does support with the site whose multiple store views.
Since there is only one store view per store on your site so that the module doesn't work in this case.
For more product information, please refer our Magento 2 Storeview Flags page.