@Accommand what router do you have?  Go to the support page for it, there are usually a bunch of videos there to show settting up.

  @Accommand 

Don't know the MODEL of your Router, but newer ones do not have instructions for a Browser to set up the router. You you 'knew' how to do it before, even then, the GUI doesn't have all the feature/settings to set up. You must use a Phone/Tablet's Deco or Tether App, depending on if you have a Deco or Standard Router. Still, you need to know the info printer on the bottom label of the rouuter  to access it and its password.

All these instructions should be on the box or a QR code.

For Instance, my Archer BE230 on the end of the box at the botton on one side has this:

You should see something similar if those are required. Note that my router as stated in the screen capture also includes a "Quick Installation Guide" that is also on the support page for the router.