OpenNDS: customising authentication

I'm getting confused in how to approach a simple home use of opennds.

What I want:

  1. To have an open guest ssid (as an aside, using OWE)
  2. To have a splash screen presented when a guest tries to use the ssid.
  3. To have them provide a name and click continue for access (but not immediately).
  4. For the admin (ie me), to be notified that someone wants access (say via telegram).
  5. For the admin to approve or reject access.

I'm struggling with how to wire this up. I don't think I need FAS. I thing hooking into binauth via custombinauth.sh is the way to go, but before I jump in I was wondering if there is a better approach.

Are there any example of simple OpenNDS authentication? For example a splash screen asking for a static shared password?

This was a great help: