President Biden echoed one of former President Trump's famous phrases by calling to politically "lock him up," a statement that quickly went viral across social media. Now Biden did say that but it is a bit out of context and hypocritical since Trump has made threat to lock up people that oppose him. Fox News is just riding off of conspiracy theories again and in this case just one about Biden and Harris wanting to "lock up" their opponents. It's not true and also there are legitimate crimes Trump has committed, we all know what they are.
Here is a fact check with context about what Biden meant by it
https://www.nytimes.com/2024/10/22/us/politics/biden-trump-lock-him-up.html