There is no evidence of widespread, systematic voter fraud in the US 2020 elections.
Trump's claims have ranged from 'more people voted than the number of people registered in a state,' and 'the dominion system deleted 2.7 million votes for President Trump nationwide' and many more, but claims around voter fraud made by him have been repeatedly debunked and no credible media organization has found widespread evidence of voter fraud. Trump and his aides have presented no actual evidence of "illegal" votes at all. The Trump campaign has also filed lawsuits in some key states, including Pennsylvania and Georgia. However, in many cases, the campaign is dropping lawsuits or their lawsuits have been dismissed by the court.