Here is what Trump said:
“What China really treated the world badly on was, they stopped people going into China, but they didn’t stop people going into the USA and all over the world,” he said. “You couldn’t fly out of Wuhan to go to Beijing and or to any place in China… you could fly out of Wuhan, where the primary problem was, to different parts of the world. What’s that all about?”
Quoted in this SCMP article:
(Reminder: Niall Ferguson, who first made this allegation in his Sunday Times of London column, has conceded he has no evidence to support it: see https://danielabell.com/2020/04/21/did-the-chinese-government-deliberately-export-covid-19-to-the-rest-of-the-world/)
Please see this article by FactCheck.org, a political fact-checking website run by the Annenberg Public Policy Center at the University of Pennsylvania:
They support my argument that Ferguson’s allegation (twice repeated by President Trump) has no basis in fact.