You don't, because JSX is not required for react. This isn't even just a theoretical point, but something I've actually done in the past several times; it's very convenient to just try something out by throwing react into a script tag and then just writing a small prototype or something without utilizing JSX and thus avoiding the need to set up a build system and everything else. I would still use JSX for larger projects, of course, but it is mostly just a small quality-of-life improvement, and I'd be using react even if JSX didn't exist, as the actually important parts of the library are not about JSX.