The App Store Connect API only begins making data available from the moment you send your first request. It does not backfill historical data before that first query.
This is a limitation of the Apple App Store API itself, not of Catchr.
How to trigger your first request in Catchr:
By creating a chart on Looker Studio that uses the Apple App Store data source
By running a query via the Google Sheets add-on
By making a call with the Catchr API
By setting up a scheduled job for a database in Catchr
After you have performed one of these first requests, allow 24 to 48 hours for the API to process and begin returning data. If no request is made, the API will not retain data for any days before the current one.