NVG599, VPN and IBM's Quad 9 DNS

I received an AT&T Arris NVG599 (residential gateway) modem, router, wifi access point and now want to use a VPN as well as IBM's new DNS numbers, which IBM calls Quad 9. I find many posts for the NVG589 -- almost none on point for the 599. Zero post about Quad9.

I've searched the 'net extensively, looking for straightforward instructions on doing either of the above. No luck. I've looked at these sites:

https://forums.att.com/t5/AT-T-Internet-Equipment/VPN-access-issues-with-NVG589/td-p/3991078

https://forums.att.com/t5/AT-T-Internet-Features/How-to-put-the-Motorola-NVG589-in-bridge-mode-or-as-close-as-you/m-p/3552057#M39255