"Invalid Host header" with reactjs, nodejs in Docker

Question

I was following this tutorial to set up my react app on Docker. https://www.section.io/engineering-education/build-and-dockerize-a-full-stack-react-app-with-nodejs-and-nginx/

I don't have a database in my app and don't use axios so I skipped those parts. The problem is now, when i launch this command

$ docker-compose up --build

I get an invalid host header when i try to go to localhost:3050.

Has anyone had the same problem before?

Thanks !