How to DHCP public IPv6 addresses for clients?

[lovemilk2333]

Hi
I use Adguard Home as DHCP server and disabled dhcp services in opnewrt
I have a LAN with a public IPv6 adderss (like 240e:xxxx:xxxx:xxxx::1/64), but the IPv6 will change each PPPoe re-dial-up, clients use this DHCP cannot get a public IPv6 because I cannot set DHCP range as like use LAN IPv6 range, I can only set a static IPv6 range.

I tried to set ra_slaac_only: true and/or ra_allow_slaac: true, but clients also cannot get any public IPv6s, want should I do to DHCP my public IPv6 address?