How to display mathematics equation from OpenAI API output

Question

It seems that ChatGPT use KaText to render math, but when I paste API output to KaText Demo website. It goes error.

（Gauss's Law）:
   \[
   \nabla \cdot \mathbf{E} = \frac{\rho}{\varepsilon_0}
   \]

https://katex.org/#demo So How should I display it in frontend?