How to use Global Keys to transfer information among widgets in flutter

i have a UserAccountDrawerHeader in flutter drawer and i need to display information of accountName and accountEmail based on signup/login credentials so i've added global key in extending state widget but i'm not able display that credentials in the drawer page after adding

"String name,email,password;
  MyHomePage(
    {Key key,@required this.email,this.name,this.password}
  ) : super(key: key);"

this thing in drawer page.