Just have to accept the fact that the guy is a psychopath, pathologic liar and, now, a really, really bad loser. When you lose by 5, 6 or 7 million votes, it's unlikely to be anything other than lots of people want to see you gone

. You notice he's not challenging the increased Republican wins in the state legislatures, and in the House of Representatives as potential Republican fraud? I wonder why? Or the fact that many registered Republicans split their ballot to vote for Biden as President, and for Republicans in the rest of the ballot? Which accounts for the Presidential results and the legislative votes. The criminally dishonest guy lost despite sending checks with his name on them to tens of millions of Americans. That takes some doing.
Some folks like to see reality as they want it as opposed to how it actually is. Hence, the fact that despite the total lack of hard evidence, half of Republicans believe the election results were different from what they were. Almost totally impossible to engineer the results artificially, but their feelings are hurt, I guess.