A downsell is the second attempt. When the buyer declines the upsell, instead of ending the funnel you offer a reduced version, a shorter plan, or a lower price, without asking for the card details again.
It works because the decline is almost never about the product, it's about the value at that moment. A well-calibrated downsell recovers part of the revenue the funnel would otherwise lose entirely, and it doesn't cannibalize the main offer, because it only appears to those who already said no.