BS challenged CO to a debate and she apparently accepted.
Not exactly how it happened.
She posted on Twitter asking for anyone who could help her set up a debate with Ben on "Israel and the current definition of antisemitism."
Ben responded with a time and date (and reminding her that he had offered to speak to her privately or publicly on the topic).
She tried to make all sorts of ridiculous "moderator" suggestions, and in the end said she would be in touch privately to work out the details.