Changing Screens

Hi im having trouble with my app, it has 3 screens and when loaded I can change the screen once by using a button ive created but after that it wont change. Is there a navigator tool im missing or anyone know how to fix this? Cheers ( i've attatched the buttons ive used)

are you saying, you have problems switching screens with the companion app?

did it work after building your app?

thanks for the help its working now