RM500Q adaptation to openwrt

Hi! I am adapting to RM500Q 5G cellular network on openwrt, dialer Quectel-CM version 1.6.4, driver Quectel_ Linux_ PCIE_ MHI_ Driver_ V1.3.4, we are unable to obtain the DHCPv6 prefix provided by the network supplier. How can we solve this problem? He’s normal for IPv4

Do you see any evidence that your carrier can assign a prefix?

I use the official QMI dialer provided by OpenWrt, which can obtain the/64 prefix

My question was about “assign”, not “obtain”. See the difference?
Just to be clear - are you talking about Prefix Delegation (PD) or just a single /64 that is assigned to (W)WAN?
It is also unclear what you actually use - in the 1st message you say “dialer Quectel-CM” but later it is " official QMI dialer provided by OpenWrt".

I am using the Quectel CM provided by Quectel, but he cannot obtain the PD prefix delegation provided by the network provider. I am very confident that the network provider can assign a prefix (PD)

If you’re using OpenWrt I suggest asking in their forum.
It will be good to show a proof that prefix is available from the provider.
I’m not sure if these commands are supported by your modem, but please try