To add a device to an AVG account, you can download and install AVG programs on the desired device. Once you installed the program, you need to enter the activation code to turn on your subscription. If you want to add an Android device to an AVG account, you have to send an invitation from an existing device with AVG installed on your Android device.
Then you will get an email to open the app and go to the menu in the upper right corner. After that, you will be required to tap Enter Invitation Code. Enter the code from the email. Once you enter the code, you can access the AVG account on another device.