Log in problems

Hi, I'm having trouble connecting my new sim card to my Netgear Night Hawk m1. When you try to connect to the router and network via mobile phone, you are asked to log in (locked wi-fi), which I do with admin and my password. Will m1login network. Can't find anything there that can be changed? The Netgear app cannot be accessed at all as it cannot find the router because I cannot access the internet. The router has worked with previous SIM cards. What to do?