There are two ways to install Headwind MDM launcher: by installing APK and by scanning a QR code. See more details here: https://h-mdm.com/compatibility/
The main difference is that, when you installed the launcher as an APK file, there is no option of silent installation and update of other apps: the user must confirm each installation or update.
Also, the QR code based enrollment is in general faster and more suitable for bulk enrollment.