I’ve heard several people say this here and elsewhere. The President went to court many times in the months prior to the election to stop these unconstitutional changes to election practices but he lost those cases. Either the court refused to hear the case or ruled in favor of the states.
In Nevada, these weasels called a special session in July to make these nefarious changes so his challenges were rebuffed.
There is only so much he could do since each state legislature determines how to conduct the election within their state.
The “President” did not go to court, it was the “Trump campaign” and several states and legislators. He did not exert the DOJ or FBI to secure the required hard evidence of computers, FBI interviews, court warrants etc...