Use DDNS (noip.com) with ngrok

My ISP uses CGNAT so I cannot use portforwarding to access my server. I am using ngrok as a tunnel but everytime I restart, the address changes. So I thought of using no-ip domain as a persistent address and updating it whenever I restart ngrok. But when I use the DDNS domain it gives me a "tunnel not found" error.

In the ngrok documentation, there is something about whitelisting domains which requires premium but I dont understand how ngrok can know I am accessing from another domain when the DNS is resolved in the DNS server.

HTTP request contains the hostname and it is checked by ngrok server application.