How can I add foldable code or text when answering someone’s question on Stack Overflow?

How do I add foldable code or text on Stack Overflow when writing a question or an answer?

<details><summary>Click to expand!</summary>```HTML<h1>Hide this until someone presses the show/fold button</h1>```</details>

Hide this text until someone taps the show/fold button.

This is what I saw on GitHub and wondered if you could have this on Stack Overflow?

https://gist.github.com/pierrejoubert73/902cc94d79424356a8d20be2b382e1ab