Even if President Trump authorized the movement to Mar-A-Lago, in June 2022 citizen Trump did not have the authorization to have classified documents moved. Now you could argue it was just Butler and Nauta moving these documents and not Trump himself, but that still doesn’t mean Trump had need-to-know to keep these documents on site and that the documents now belong to their authorizing agency. Even if the executive branch was the authorizing agency, the Biden administration is the successor of function and owns these classified documents.