According to The Guardian, Trump made several calls to his “top lieutenants” at the Willard hotel in Washington, late at night on January 5 and into the early hours of January 6, 2021. On at least one call, he sought ways to prevent Biden’s election from being certified:

The fallback that Trump and his lieutenants appeared to settle on was to cajole Republican members of Congress to raise enough objections so that even without Pence adjourning the joint session, the certification process would be delayed for states to send Trump slates.

It was not clear whether Trump discussed on the call about the prospect of stopping Biden’s certification by any means if Pence refused to insert himself into the process, but the former president is said to have enjoyed watching the insurrection unfold from the dining room.

But the fact that Trump considered ways to stop the joint session may help to explain why he was so reluctant to call off the rioters and why the Republican senator Ben Sasse told the conservative talkshow host Hugh Hewitt that he heard Trump seemed “delighted” about the attack.

It’s not as if it’s a huge surprise that Donald Trump would have his fingerprints on an effort to overthrow our democracy. But it’s important to know what, exactly he did and tried to do – as well as who did what to help him. I suspect that whatever information was leaked to The Guardian will eventually find its way into the January 6th Committee's report, if not sooner.

Laughably, the Trump lawyers are claiming they only cared about voter fraud:

Several Trump lawyers at the Willard that night deny Trump sought to stop the certification of Biden’s election win. They say they only considered delaying Biden’s certification at the request of state legislators because of voter fraud.

But neither Trump’s DOJ nor any of the state legislators was ever able to provide any evidence of voter fraud. They still haven’t.