Probably never. Entrapment in US law is when the government creates the crime. Offering up the opportunity doesn’t create it, just catch those looking.

Maybe if they started heavily advertising it, sending spam to the same person continuously for months on end.

Even if an undercover cop asked you to hire a hitman and you say yes. Entrapment is more when you say “No” and the government agent keeps on begging you until you give in.