He's trying to refute "Trump is on record for provably lying all the time about just about everything" by suggesting Politifact's count is rigged. It's standard Trump's rabid fanbase, you've seen it plenty of times.
Politifact cites their sources, consults experts, and explains the evidence. Trump does none of those. Even if it wasn't a lie-vs-lie count purely by the numbers, Trump would still lead because of the scope. He just makes shit up, or worse, takes things which have been made up (like conspiracy theories) and runs with them. Trying to somehow Whataboutism this away by claiming Politifact is biased is like equating me with the Unabomber because I got a speeding ticket.