I noticed that my app returns this HTTP response header:
Server: TornadoServer/4.5.2
Is it possible to change it to custom?
You can use the RequestHandler.set_header() for the headers you want to add or change. Here is an example
RequestHandler.set_header('Access-Control-Allow-Origin', '*')
RequestHandler.set_header('Access-Control-Allow-Methods', 'POST, GET, PUT, DELETE, OPTIONS')
RequestHandler.set_header('Access-Control-Max-Age', 1000)