When you automate a Coverage Report, the report will only populate with articles published from that point on. If you would like to add any coverage that's been published already, you can quickly backfill your Coverage Report.
Run an Articles search for the query you want to use to populate your report
Select individual articles by clicking the checkbox to the left of each headline OR bulk select the entire list of articles by selecting the checkbox at the top of the results page and choose Select all
Click Add to Coverage Reports in the top-right
Type in the Name of your Coverage Report
Select Create New or select your existing Coverage Report