Thank you for your reply.
1. Based on your screenshot, you are a Beta tester of Android System WebView. Have you signed up Beta program for any app developer? If so, please contact the app developer.
2. Have you ever rooted or unlocked your device?
3. Please check the search result of Google Play Store>Android System WebView more carefully. Sometimes, the search result will have "Android System WebView" and "Android System WebView Beta". Please tap "Android System WebView" rather than Beta version.
4. Your current firmware version
Settings>System>About Phone>Build Number