Problem Generating apk ionic 3

I'm developing an application that needs to read a Qr Code, but I have a problem generating the .apk in ionic 3.0. When I upload the application in the ionic view it works normally (open the camera and it reads), in the NOX emulator it also works, however when it generates the .apk the application opens normally but the capture button does not work, what could be happening? / p>