You'll need to either insert BR tag appropriately in the resulting string, or use for example a PRE tag so that the formatting of the stringify is retained:

var data = { a: 1, b: 2 };

var Hello = React.createClass({
    render: function() {
        return <div><pre>{JSON.stringify(data, null, 2) }</pre></div>;
    }
});

React.render(<Hello />, document.getElementById('container'));

Working example.

Update

class PrettyPrintJson extends React.Component {
    render() {
         // data could be a prop for example
         // const { data } = this.props;
         return (<div><pre>{JSON.stringify(data, null, 2) }</pre></div>);
    }
}

ReactDOM.render(<PrettyPrintJson/>, document.getElementById('container'));

Stateless Functional component, React .14 or higher

const PrettyPrintJson = ({data}) => {
    // (destructured) data could be a prop for example
    return (<div><pre>{ JSON.stringify(data, null, 2) }</pre></div>);
}

Or, ...

const PrettyPrintJson = ({data}) => (<div><pre>{ 
    JSON.stringify(data, null, 2) }</pre></div>);

Working example

Memo / 16.6+

(You might even want to use a memo, 16.6+)

const PrettyPrintJson = React.memo(({data}) => (<div><pre>{
    JSON.stringify(data, null, 2) }</pre></div>));

It looks like you missed the stringify step:

function sourcePage(){
 const navigate = useNavigate();
 var values = JSON.stringify({id: "someData", startd: "someData", endd: "someData"});
 values && navigate(generatePath("/harvestcalendarmonitoring/:values", { values }));
    } //with useNavigate and generatePath

However, make sure generatePath is also URL encoding this string values or else you will likely have an invalid URL.

When it comes time to parsing the string back into an object, be sure to call JSON.parse

Just use JSON.stringify method in order to turn an javascript object into JSON text and store that JSON text in a string.

Also, you can use JSON.parse which turns a string of JSON text into a Javascript object.

let state = {
    name : "Example",
    age : "21",
    description : "Some text here."
}
console.log(state);
console.log(JSON.stringify(state));