With the Admin UI we introduced the super user, it is created with the initialisation of the Admin UI and will be shown with a success message in the server logs.
The super user has access to the server and can change settings that may crash the server and make it unresponsive via the frontend and api, like changing funding sources.
We also added a decorator for the API routes to check for super user.
There is also the possibility of posting the super user via webhook to another service when it is created. you can look it up here https://github.com/lnbits/lnbits/blob/main/lnbits/settings.py `class SaaSSettings`
Admin Users can change settings in the admin ui as well, with the exception of funding source settings, because they require e server restart and could potentially make the server inaccessible. Also they have access to all the extension defined in `LNBITS_ADMIN_EXTENSIONS`.
Here you can design the interface, it has TOPUP to fill wallets and you can restrict access rights to extensions only for admins or generally deactivated for everyone. You can make users admins or set up Allowed Users if you want to restrict access. And of course the classic settings of the .env file, e.g. to change the funding source wallet or set a charge fee.