If you've already subscribed to Vaulty's automatic backup, just do the following and your files will backup automatically:
1) Have the newest version of Vaulty on your device
2) Authorize Vaulty to use one of your Google accounts for automatic backup
3) Make sure you are using the same Google account on your device that you used to purchase the subscription
***Automatic backup will only occur when you are connected to WiFi and are either charging your device or have at least 50% battery power on your device. You also have the option to set automatic backup to occur on mobile data without WiFi.