Presidential elections are run by states. They keep track of who is registered to vote, they run polling places, they print ballots, they own the machines that are used to cast and/or count votes, and every election worker ultimately reports to - and is paid by - their governor.
The president has no role, at all. He can’t hire election workers, can’t access polling places, can’t look at voter registries, and has no voting machines. Intentionally, to avoid schemes like yours.
So to extend the dialog:
Biden: Hey, all the governors flaked out so I’m hiring people to rerun the election myself. I’ll pay you $10,000. Bring 699,999 of your friends, we gotta build a whole new bureaucracy from scratch.
Passerby: Is that even in your budget?
Biden: Maybe. Maybe not. I’ll pay you $100,000! Also, order a voting machine on Amazon. I’ll reimburse you later.
Passerby: I’m never getting paid, am I?
Biden: Are you helping me or not? Also I need your home address, it’s gonna be a polling place. I’ll throw in $200,000 for your legal fees if you’re arrested for election fraud, like those false electors in 2020 that you bear no resemblance to!
Passerby: No thanks.
Biden: But I got immunity, baby! Immunity!
No, they aren’t. Because it’s a semilog graph.