This is slightly incorrect. The Vice President doesn't certify the election. The Vice President counts the votes. What happens before this is that governors certify electors of which to send officially to DC.

Now, let me try to clear up some shenanigans.

In 2020, it was legal for the Vice President, as it had been for the entire history of the country, to choose which electors to count. If he refused to count electors sent to him & certified by the governor he could do that. The Democrats claimed that despite this happening 3 times, this (in and of itself) was an insurrection. Since it was somehow an insurrection that never happened before, Kamala Harris herself pushed for a bill to make sure that the VP's role was now ceremonial in nature, and could only count certified slates of electors.

The governors of the state certify the slates of electors of which the governor claims represent the state's final popular vote. THERE ARE ALWAYS A REPUBLICAN AND DEMOCRATIC SLATE OF ELECTORS PREPARED AHEAD OF TIME. Depending on the vote outcome, the governor chooses one to certify. As I mentioned previously, the VP has previously counted uncertified slates of electors. The VP also refused to count certified slates of electors. This was legal until 2021.

What Trump and Trump supporters got in trouble for was that they sent uncertified electors to DC, and claimed they were "duly elected". This has been declared insurrection. Just so we're clear. The DOJ claims that because they called themselves "duly elected" and not certified, this is fraud. It's not. In fact, anyone, including the Libertarian and Green Party, can send slates of uncertified electors. What they really didn't like is that Trump managed to send slates of electors that weren't the official pre-designated republican slate. Again, this is legal, but this is being treated as terrorism by the feds.

The problem with Harris is that she shot herself in the foot 3 years ago and didn't know it. She can't stop the count. She made it criminal for her to do so. Now, it's possible that she could break the law and do it anyway, creating a constitutional crisis, an impeachment struggle, and a House of Representatives vote. I've argued this may still happen, but it's unlikely if Trump does well.

The real danger here comes from the governors. People like Shapiro and Hobbs may simply certify the Democratic electors regardless of whether or not the vote count has stopped, or what it's at. If the Republicans send up their electors, those electors may go to jail, causing a constitutional crisis. If Trump orders them, he may be arrested, causing a constitutional crisis. It won't get her any new votes, but it won't get Trump to 270.

However, this requires Harris to have the political capital that could afford a major constitutional crisis... I don't think she has it, and I think a few people, like Shapiro himself, would rather watch her fail, that risk it all on a House Vote for president that Trump could potentially still win.