He has to prove it in court if he wants accurate compensation, but that’s not really on the table atm.

Did you read the article? I’ll quote the relevant section.

During his speech at CogX Festival on Thursday, Fry played a clip to the audience of an AI system mimicking his voice to narrate a historical documentary.

“I said not one word of that—it was a machine. Yes, it shocked me,” he said. “They used my reading of the seven volumes of the Harry Potter books, and from that dataset an AI of my voice was created, and it made that new narration.”

They are replicating his voice.