I just downloaded Bluestacks and am trying to open an APK file, but everytime I download an APK my Windows 10 saves it as a PDK. Also, I don't see the option on Bluestacks to handle the APK file.
Here are some instructions on how to download and install an APK.
Make sure the source of the APK is a trusted site. Download the APK.
After downloading, it will have .apk as the file extension. If it has a different extention, that would mean that you downloaded the wrong thing!
Move the file to BlueStacks. This can usually be done by dragging the file, and dropping it in the file manager in BlueStacks.
Now, in BlueStacks, press on the file, and Press on install. It will then ask you to allow downloading from unknown sources, tap OK and it will install the file.
The APK will now appear as a regular app together with the rest of the apps that you have downloaded.