Step 1:

Navigate to https://www.kwivuza.rssb.rw/rw/auth/login 

Step 2: 

Click "Receive SMS"

Step 3:

Put in your registered phone number and click "Continue"

Step 4:

Type in the 5-digit code you received in the SMS.

Step 5:

Click "Sign in."

You are successfully logged in using SMS OTP.