For login in bulk SMS portal use following Steps:
2) Enter your username & Password
3) Click on Sign In option
If your IP Address is changed then you need to verify your Mobile Number and then after you are able to log in SMS control panel.
3) You can enter your Registered Mobile Number (RMN) starting with 91XXXXXXXXXX in the column and click on Next Button. So that you can get the OTP.
4) After that, you can get the OTP on your registered mobile number. Enter that OTP in the column and click on verify button.
5) You are logged in SMS control panel successfully.