It is important to note that the match data coverage CANNOT be changed once a game has kicked off.
To change the match data coverage on an already created match, that has not yet kicked off:
Click Matches in the left hand side dashboard.
Find the match in the Live and Upcoming list.
Click the 3 ellipsis next to the match you wish you edit.
Click Settings, the first option in the list.
Navigate to the top left of the screen and find the Stats section between Match and Overlay.
Adjust the data coverage as desired.
Click Save, displayed at the bottom of the screen.
You have successfully adjusted the data coverage of an already created match.