You just post a React Developer Job Description on different job portals, and then interview and hire developers who possess skills relevant to your needs. This selection method helps you make choices, but it might be time-consuming and difficult to get the right talent for that position.
Check that the developer is proficient in React and its core concepts such as components, state, props, lifecycle methods, hooks, etc. Also, make sure that they are familiar with modern JavaScript (ES6+), HTML, CSS, and related technologies.