How to fix "Invalid Host Header" for a React component

I had my first static site deployed at sea-lion-app-dpidq.ondigitalocean.app . Then I added a React webapp component (after following this tutorial: https://react.dev/learn/tutorial-tic-tac-toe) in the same project. DigitalOcan gave me a new HTTP route to sea-lion-app-dpidq.ondigitalocean.app/forest-visualizer but when I try to access it I get the error “Invalid Host Header”.

When deploying the React component, I did not specify any HTTP requests in anyway as I was crueless how to manually configure it. Many StackExchange websites (ex. https://stackoverflow.com/questions/43619644/i-am-getting-an-invalid-host-header-message-when-connecting-to-webpack-dev-ser) say to fix disableHostCheck, but I do not have any file that specifies the script.

Does anyone know how to fix the issue? Please also let me know if this is not enough information to debug.