Once you have your application working and ready to be deployed you can create a production version by running (from the root of your project)
npx frontity build
This command will generate a build folder containing both your (isomorphic) React app and your Frontity (Node.js) server. This folder can be deployed to any hosting that is prepared to serve a Node.js app. The content of this build folder will be used by the command:
npx frontity serve
Which is used to launch the Frontity app in production.
Here you have some guides about how to deploy a Frontity app in some popular hostings:
Sometimes you will want to serve your assets (also called "static files" like images, fonts, JS chunk files) from another domain or from a CDN. In this case, you can modify the publicPath parameter when you run npx frontity build.