How made a VPN under NAT

Hi, Please help on these situation. Im rookie.
My Device:
Model: Ltap mini LTE kit
OS: 6.42

Already setup: VPN (enable IP CLOUD), PPTP and LTE sim card

But have th followin error: DDNS server received request from IP 201.227.226.144 but your local IP was 10.168.40.200; DDNS service might not work.

i cant connect to my address
############.sn.mynetname.net

Your ISP is using CG-NAT and you will have big problems with any port forwarding.

Thats right.

Any one know a service or script to work over these situation.

Any idea.

The solution is to get public IP address, from this ISP or from another. Or in worst case, from some tunelling service.