I installed last version of react-toastify.
When I use simple demo toast:
toast.error("TEST", {
position: toast.POSITION.BOTTOM_LEFT
});
There is not "red" style - see image, why? What is wrong with my code?
In another component I have a <ToastContainer /> container.

You need to import the CSS file.
import 'react-toastify/dist/ReactToastify.css';
I import still not working!
Working for me in the development but not after building
Developement Server :

After Build In production :

I have the same issue.
In my project, I made a new file toast.css and pasted styles from this path: node_modules/react-toastify/dist/ReactToastify.css.
And in my file I import something like this:
import './toast.css';
import 'react-toastify/dist/ReactToastify.css';
Then i can build my app with styles from Toastify.
I have same issue.
No, simply importing css does not help at all.
It seams tricky to add react-toastify to already mature react app.
Seems the only way to make it work is to add it to your react app from very beginning (right after you run create-react-app etc.) with little or none boilerplate code, otherwise it is not working straight out of the box when I try to add it to my blueprintjs or material-ui based app..
Had to switch over to react-toast-notifications
that really worked out of the box with no effort, just plugged it to my already existing code
And react-toast-notifications
is also can be used as a react hook, which is kind of awesome.
Most helpful comment
You need to import the CSS file.