Instead of apk format file without any extension is created while publishing an android app

Question

I am new to publishing android app to google play store. When i am trying to publish app using signed release key and follow all the steps in the previously posted questions, my app is created, but without any extension.

Please guide me in this issue.

Below was an image of that file created format in the output.(problem is created file was not in apk format). I dont know where i missed.

Answer 1

I tried same steps for an other app which work perfectly and generated an apk file. But unfortunately this apk was generated only after giving the extension propely.