He did and replaced the original executive order from Trump with his own and signed the PAFACA into law last year which effectively supports the TikTok ban.
Biden didn't stop it because he also supported the ban as well, which is even worse.
So TikTok would have been totally banned if either Biden or Harris won the election.
Biden and Harris's arguments against Trump fell flat when they had no explanation for why they continued almost everything awful he started, while also still claiming it was awful. "I was going to send her a Maga hat."
I thought Joe Biden signed the law?