The National Football League Players Association sued DraftKings in New York federal court on Monday, accusing the sports-betting giant of refusing to pay what it owes for using NFL player likenesses on non-fungible tokens.

The NFLPA said DraftKings broke an agreement, opens new tab to license the players’ name, image and likeness rights by refusing to continue paying licensing fees after shuttering its NFT trading-card business last month.

“The impetus for DraftKings’ decision to repudiate its license agreement with Plaintiffs is simple: the once white-hot market for NFTs has cooled down,” the lawsuit said. “Buyers’ remorse, however, is not a basis to terminate a contract.”

A spokesperson for DraftKings declined to comment on the complaint. Attorneys and spokespeople for the NFLPA did not immediately respond to a request for comment.