The goal is to build a component for input autocompletion (see https://en.wikipedia.org/wiki/Autocomplete if unsure what autocomplete is).
First - do your initial analysis. What a great user experience using this component should look like? What other things should you consider before you start with the implementation? Write it down.
Second - build a prototype. You can use React.js or the stack you are the most comfortable with. There is no need to spend a ton of time on it, but it should be enough to showcase your skills and ability to write clean and well-architected code. Pick any dataset you like.
Third - write down a list of features you have decided to skip in the prototype, but you think should be included in the final version. Include your effort estimates. Think both in terms of the customer-facing features (e.g., "I would do ... to improve the usability for visually impaired people. It would take 0.25MD to implement.) and technical concerns (e.g., adding the component into Storybook).
Send me the results of all of the steps above.