Managing Geolocation in Your Browser
If you've declined giving access to your location to a web page, re-enabling your browser to know where you are physically located requires you to manually give that permission. Every browser has a different means for you to give that permission
There are many different versions of the above browsers and there is no real standard means to allow location access for a website after you've blocked it. Usually there will be some sort of Lock or Info icon available in the address/location bar, or as a menu item labeled Page Info or similar.