The UX designer researches the target audience, thinks about the structure of the product, analyzes user paths, and the UI specialist visualizes the concept. Since UX- and UI-design work are closely related, most often they are done by the same I've read a lot about how to hire here
https://cieden.com/how-to-hire-a-ux-ui-designer-in-2022 What should UX UI Designer be able to do?
The main requirements for UX/UI Designer. Fluent in prototyping tools: the most popular now is Figma, a bit less - Sketch, Illustrator, Adobe XD, etc. Experience in drawing UI elements, illustrations, icons. Basic knowledge of typography and composition