Open about:history so you can see and refresh it after each button press.
about:history
history.pushState('/?a=b')
history.pushState('/#a=b')
history.replaceState('/?a=b')
history.replaceState('/#a=b')
location.assign('/?a=b')
location.assign('/#a=b')
location.replace('/?a=b')
location.replace('/#a=b')