If you’re having an issue restoring the in-app purchase, please make sure the app is downloaded from the Play store while signed in with the same account the purchase was initially made with. Please ensure the latest Google Play Services is installed prior to restoring the purchase.
In the premium features screen (Figure 1), the restore button at the top right, or at the bottom (Figure 2) will restore your purchases. An app restart may be required before the premium features are unlocked.
Figure 1: Premium Features in the main menu
Figure 2: Restore previous purchases
If the purchase is still not restoring, please reinstall the app. Your AutoMate settings can be backed up first under Settings > Support > Backup to Google Drive, and then restored after the reinstall.