WAN IP Address given by the modem is not the real one

Hello,

I have a modem Huawei B890-66. I want to have access to the management remotely so I allowed the "Remote management(via Wireline and 4G network)". It give me an ip address like https://10.168.X.X:443. It did not work when I try the address on the Internet. When I go to https://www.whatismyip.com/ to check my real IP address, it give 142.169.X.X. As you can see, the IP address gave by the modem is not the real one.

I tried to reboot the modem without success.

Do you have a clue?

Thanks!