Depending on what you have available there are multiple ways to run Flask applications. You can use the builtin server during development, but you should use a full deployment option for production applications. (Do not use the builtin development server in production.) Several options are available and documented here.
If you have a different WSGI server look up the server documentation about how to use a WSGI app with it. Just remember that your Flask application object is the actual WSGI application.
For hosted options to get up and running quickly, see Deploying to a Web Server in the Quickstart.