Ensuring access only my App

Guys, someone here has a solution to ensure access to my back-end only my App Ionic?
I’ve used the token level of a plugin in native C level in Java / Object-C was generated a token.
My App has no authentication is an App to public information, but would like to restrict the back-end only receive requests from my App.
I know that in the AngularJS Javascript level it’s easy to reverse the App code and figure out how the token