Once you have downloaded the ZIP file on your PC, follow these steps: 1) Right click on the file, select 'Extract All' and follow the instructions to unzip it. 2) Run the BlueStacksInstaller.exe file to install this Android emulator on your PC. 3) Now, in BlueStacks, click on ‘Play Store’ and log in with your Google account. 4) Go back to the BlueStacks home screen and drag the WhatsApp Business.apk file over it, and you’re good to go. If this doesn't work, go back into 'Play Store' and search for the app to install it directly from Google Play.