API request doesn't work with my APP

Tell us what’s happening:
Hello Developers,
I’m trying to finish my Random Quote Machine. I build a small React App and I’m using the fetch method for calling an API that allows me to access to random quotes. Unfortunately, It doesn’t work. I tried to test the API with Postman and if I use the API though internet it actually works. How is possible?

PS the page stay with the

Loading

Your code so far
class App extends Component {

constructor(props){
	super(props);
	this.state = {
		items: [],
		isLoaded: false,
	}
}

componentDidMount() {

	fetch('https://jsonplaceholder.typicode.com/users')
		.then(res => res.json())
		.then(json => {
			this.setState = {
				isLoaded: true,
				items: json,
			}
		});

}

render() {

	var { isLoaded, items } = this.state;

	if (!isLoaded) {
		return <div>Loading...</div>
	}
		else{

	    return (
	      <div className="App">	
		      	<ul>
		      		{items.map(item=>(
		      			<li key={item.id}>
		      				Name: {item.name}
		      			</li>
		      			))};
		      	</ul>
	      </div>
	    );
	 };
}

}
Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36.

Your API is not for quotes. I can not see it. Why do you try other resource? In github you can search, for example.

I updated my App using quotesondesign api-v4-0, but I have the same problem.

Is a CORS error? Is because my browser doesn’t take http request?
I know that sounds stupid, but If I run the API through Postman, it works! May I ask you why?