How should I add a line break in a string?

Question

I have an email component made in react, but I want to have its body text on different lines.

Here's the component:

export const Mailto = ({ email, subject = '', body = '', children }) => 
{
    let params = subject || body ? '?' : '';
    if (subject) params += `subject=${encodeURIComponent(subject)}`;
    if (body) params += `${subject ? '&' : ''}body=${encodeURIComponent(body)}`;

    return <a href={`mailto:${email}${params}`}>{children}</a>;
};