Enable Global Background App Refresh on your iPhone
If you have tried to turn on Background App Refresh on your iPhone at Settings > Driversnote and found it missing or greyed out, it means you need to enable it globally.
You can find this under Settings > General > Background App Refresh
Choose that option then select Wi-Fi & Mobile Data
Once you have that turned on there, make sure it is in the app list below, then you will be able to verify it is on under Settings > Driversnote.