I tried uploading a game to google play. But I got a warning that the API level needs to be changed to a diferent one. I'm not sure how to do that in Unity as I had not configured it before. Can someone please help. I have attached a screenshot of the warning.
This question doesn't demonstrate research effort. Searching Unity Android API Level will lead you to the documentation for Android Player Settings, including:
Minimum API Level Minimum Android version (API level) required to run the application.
Target API Level Target Android version (API level) against which to compile the application.
Here you'll find a drop-down to select your target API level: