Problems using the navigator can not property 'push' of unedefined

When I try to click on the accept button to move to a navigation window through the browsers, I get the can not property error 'push' of unedefined which refers to the following code lines.

aceptar(){
      this.props.navigator.push ({
      title: 'Dashboard',
      name: 'Dashboard',
      passProps:{}
});
}