Router/Modem setup for ipv6

All of the discussion that I see on this subject seem to infer to check with modem/router manufacturer. My Asus RT-AX99 manual says to check with the ISP. When I go into the router to enable ipv6 I end up with 7 options: native, static ipv6, passthrough, FLET’S ipv6 service, tunnel 6to4, tunnel 6in4, tunnel 6rd.

Any ideas?