No Internet Connection after Factory Reset

About a month ago, I bought a router to hook up to my modem. I used the Nighthawk app to help hook up the router and give off internet. The router worked well at the time. Just now I had to reset my internet connection although I accidentally factory reset my router because I held the reset button down for too long. I go to hook up the router again, but this time it says that my connection is secured but with no internet. I go back to the Nighthawk app to set up the router again, but they want me to scan the QR code from when I first bought the router that I no longer have anymore. I choose to set it up manually, but I end up with the same results: Secured, No Internet. I made sure cellular data was turned off when I tried connecting to the internet off my phone and the connection still gave me those exact results.