Function apps aren't for UIs so no. Function apps are basically backend process runners that can either be triggered or scheduled to run. They do some work and then shutting down until triggered (or scheduled) again. There is no UI.
You can host your front end app in an Azure App Service. It is basically a clouded web server. Your backend can also be hosted in Azure App Service as that makes the most sense here if it is the API for your app frontend. Alternatively you can combine both the front and back end apps into a single project and use App Service to host just one binary. It is up to you.