Al Gore challenged the result of the 2000 election until December 13, 2000, including challenging the actions of the Florida Secretary of State.
There have been several anomalies brought to light concerning the handling and counting of ballots in the 2020 presidential election. Trump has the same right Al Gore did to use the legal system to seek explanations for those anomalies.
All the thunderous noise to the contrary coming, generally speaking, from people who never accepted the results of the 2016 presidential election, may be safely disregarded.