Your Router may offer a WiFi option. But even still that wouldn't effect your Bluetooth keyboard if thats what you have.
Do you have an Apple USB keyboard? I’m suspecting your keyboards battery contacts have corroded up. Using some white vinegar with a cotton swab (Q-Tip) see if you can wipe down the contacts if they have any corrosion on them. Using a second cotton swab wipe the area down again with some water to neutralize the vinegar. If that fails you’ll need to give a pink pencil eraser a try it will allow you to clean off the film that sometimes builds up on the contacts.