Having trouble setting up IPv6 on my GL-AX1800

Hello, I recently got my GL-AX1800 router, and have had it working for a while. However, I’ve recently ordered an upgrade to my internet from my ISP, and noticed the default modem/router they provided me with supports IPv6. However, I can’t seem to get IPv6 working from my Flint router.

The ISP I use is Centurylink (DSL), the connection is PPPoE, and I have the router behind the ISP-provided modem set in Bridging mode. I’ve read from a few places that Centurylink only supports 6to4 / 6rd, which I tried to set up from the LuCI page in the router, and I’ve not had any luck. I’m not even sure where the problem lies, so any help would be appreciated, thank you.