Mac won't open the website 192.168.1.1 (MacOS Big Sur)
You’ve got quite a catch-22 if you want the network to work before you can connect to your network. Big Sur is well tested with private non-routable networks like 192.168.X.X and since they are non-routable, you really need to get into the specifics of the local network to solve these.

You’ll need access to the router to examine and configure or change or (or access to a person that can do that for you)
You’ll need to learn a bit about routers and netmasks if the DHCP setup doesn’t work or your local and non-reputable network isn’t flat with all the machines in the same small address pool.

What are your options to manage this network or get help? Since none of that detail is on your question, we’re not going to be of any use solving your network remotely. Especially if this network has a captive portal, you may be stuck if you don’t try to open this site in your browsers one by one.

http://captive.apple.com