HMD Global has started rolling out the March Android Security update for Nokia 7 which is a China exclusive device. The update is 80 MB in size and you will receive a notification once the update is available for your device. You can also manually check for the update by going to Settings > About Phone > System Updates.
aWhat's new in this update:
This new update only brings the Google's March Android Security patch update to Nokia 7. You can find more about Google's March Security update at Android Security Bulletin.