You can do that by entering the configuration of your router. Please see the manual for your specific brand and type.
If you have a Linksys router, the default address to load the config settings is http://192.168.1.1 With default username being admin.
You may have changed these settings. Also, other routers may be different. This is just a common scenario.
If the default password has ever been changed you may have to reset the router to factory. I find that a cable connection is best when setting initial security.