No Sun Until the 4th Day in Genesis? Why Alex O'Connor Bested Dinesh D'Souza. So Unnecessary!

I saw some video of a debate between "Cosmic Skeptic" Alex O'Connor and Dinesh D'Souza. One question in which the Skeptic did well was the formation of the sun in Genesis chapter one. Why does the text have the sun not being made until the fourth day? The Christ-centered model for early Genesis can make sense of this, as it does so many other questions from scripture, science, and history.

Amazon page of "Early Genesis, the Revealed Cosmology" https://www.amazon.com/dp/B06XRLDYJB