IPoE Access- how can I achieve this?

[Nitin sidhu]

Hello
We are using IPoE as user access mechanism. The BNG/BRAS uses the option82
in the DHCP discover message and creates a username from that and passes
this username to the radius server.
All the users are in a postgres DB.
We need to wall garden any user that is not in the DB when the radius
servers looks at the DB tables.  We require that any user that is not in
the DB, the radius server should pass these attributes in access-accept
packet to the client:
1) Filter-id
2) HW-Web-URL
How can we achieve this please if this is possible? and where would we need
to add the necessary policies?
Kind regards
Nitin Sidhu