What part of English don't you understand. They authenticated the emails...
The email and others in the cache were authenticated by people familiar with them and with the investigation
They can't prove that the emails weren't placed on the laptop by Russian operatives after Hunter allegedly turned it into the repair shop (the Russians were known to have stolen emails from several democrats including Clinton) or that Hunter actually owned the laptop or turned it into the repair shop. Moreover, what's the crime being alleged? No one has ever claimed that Hunter Biden was an altar boy here. So what if Joe Biden held a meeting with someone his son asked him to meet with. What father wouldn't do that much for a son? Why would that be a crime? Why would it be a crime for a son to arrange a meeting with his father? There is no quid-pro-quo alleged or provable.
New Details Flesh Out How Project Veritas Acquired Ashley Biden’s Diary The right-wing group placed a deceptive call to the president’s daughter a month before Election Day, weeks after her stolen diary was shown around at a Trump fund-raiser.