Mike Pence was under intense pressure from the president, Trump attorney John Eastman, and the mob to not certify the 2020 election results. Chants of hang Mike Pence along with the president egging the crowd on by tweeting about the VP did not make things any easier.
Gotta give the former VP credit for hanging in there especially when the insurrectionists came within 40ft of getting him. As for John Eastman who came up with the plan to steal the election, I think Trump's White House Attorney said it best:
"'Now I'm going to give you the best free legal advice you're ever getting in your life,'" Herschmann continued,
according to his testimony. "Get a great effing criminal defense lawyer. You're going to need it.' And then I hung up on him."