This is because you are using it as a “test” and not as an “Android app”.
Open the Edit Configurations panel and click the + button. Choose the option to create a new “Android app,” and then select the correct module. Apply, and then you can remove the test configuration that you used before if you want. Then, every time you launch, make sure that you are running as an Android application, not a test, and it will automatically start upon installation.
Tomichardson
source share