Drag a show/hide object into your scene from the object panel on the left. Choose which image you want to use as the button itself in the scene.
If you look at the properties panel on the right, you will see a dropdown that allows you to select the ‘target’ for your show/hide button. This is the object that will appear or disappear when the user taps on the show/hide button itself.
The dropdown will show all the objects in the scene (including the button itself - more on this later). Select the object you want to appear or disappear.
You can also choose whether the target object will start visible when the user scans the marker by toggling the ‘Should Object Start Visible’ switch.
If you pick the show/hide button itself as a target, it will disappear when the user taps it and the user will have no way to bring it back. This can be a useful effect sometimes to make objects in a scene disappear.