c# with react front end

Hi i was wondering how someone would go about creating full stack app using react as a front end and dotnet for the backend, currently i have two folders in my project one being a dotnet web api and the other being a react application. My issue is how would you go about routing.

Like if you were to go to a profile and the route is the user's id (user/32), how would it work. Because wouldnt the client have to serve the view for that route then from the paremeter given contact the web api to get the data you get me , or have i thought about this wrong.