this seems to be working. Replaced the &amp with &body

import React from "react";
import "./style.css";

export default function App() {
  return (
    <div>
       <div className="container">
            <a className="video-email_button button-hover" href={`mailto:?subject=I wanted you to see this site&body=Check out this video https://youtu.be/yul2-4mc6mg`} title="Share viaEmail">
                <span className="video-email_button-text">Email</span>
            </a>

            </div>
    </div>
  );
}

I have a simple app where I would like the user to share youtube video to email on click here is I have tried so far

import React from 'react'

function kiki() {
    return (
        <div>
            <div className="container">
            <a className="video-email_button button-hover" href={`mailto:?subject=I wanted you to see this site&amp;body=Check out this video https://youtu.be/yul2-4mc6mg`} title="Share viaEmail">
                <span className="video-email_button-icon">
                    <ReactSVG src={shareEnvelopeSVG} />
                    </span>
                <span className="video-email_button-text">Email</span>
            </a>

            </div>
                
        </div>
    )
}

export default kiki

Here is live demo : LIVE DEMO

Unfortunately, the only subject title is added to the email, as below image shows

Why body text is not added to the email ???