wap lte could not connect to DDNS

I have a Wap LTE.
I have enabled the cloud option. But when I want to connect to it, it brings the following error:
error: could not connect to xxxxxxxxxxxx.sn.mynetname.net
please help me.
thanks

many questions.

  • this is a LTE model. is your LTE provider even giving you a public IP?
  • have you opened up firewall, so that the specific protocol and source IP is allowed to connect to the router?