atVenu cannot report Download Card sales to SoundScan. And, as of 2023 download cards are no longer a chart eligible medium and are no longer eligible for charting.
You can log your Download Card sales in atVenu for each show, just like you would any other music item. However, you are simply logging the sales quantities in the system so there's a record of quantity sold by show. The sales are not actually submitted or reported to SoundScan.