Companies such as Apollo, ZoomInfo, PhantomBuster, and others offer credit-based access to their databases. In other words, you pay upfront and use credits to buy the leads you want.
This process has two sides to it. The first is that they are grossly overpriced. Two, you must manage the process yourself, with little assistance by people who can assist you in navigating better results.
Small businesses that have the same databases for a lower price and provide maximum service assistance are the best way to get such sales leads.