allow website button for restricted site on child's tablet not working

Hi there, 

  I am trying to get the Homer app to work on our child's tablet and we are having trouble when the restricted site comes up " you cannot browse this page at "localhost" because it is restricted" I am also not able to hit the allow website button. 

 I have added www.learningwithhomer.com yet it still isn't working. Any other suggestions? If I am unable to resolve this issue, I unfortunately will have to cancel our subscription but I would like for this to work. 

Thank you :)