I think the process is that the electoral votes from each state have to be just counted by the VP unless there are objections from the house and senate.
In 2020, there only needed to be one objection, but they changed the law and now an objection has to be supported by at least 1/5th of the membership. If that happens, say 2/3 of Republicans in the house object, then both chambers meet to vote. The electoral votes are only excluded if both chambers vote for their exclusion.
So if for example, the house objects to Biden electors from Arizona and every single Republican votes to exclude them, but the Senate doesn’t agree, then the electoral votes count anyway.
The obvious problem with this is that if the state officials are corrupt and submit the wrong electoral votes, the Democrats will not have any way to stop them from being counted. So I’m sure that’s where Trump will be focusing his efforts.