JavaScript pertaining to popup blog post

popup.js

const constructPopup = () => {
    // propbably not the most efficient solution to hiding the popup
    // but the code is here if for whatever reason you might want to use it
    document.body.innerHTML += popupString;
}

const popupString = `
<div class="popup outer">
    <div class="popup inner">
        <button class="close">x</button>
        <img src="giphy.gif"/>
        <h3>Here is your popop!</h3>
        <p>If you liked this tool, please leave a tip or follow me on Medium!</p>
        <p>Thanks for using the custom popup!</p>
        <a href="https://paypal.me/mattcroak?country.x=US&amp;locale.x=en_US" target="_blank">Paypal</a>
        <a href="https://matt-croak.medium.com/membership" target="_blank">Medium</a>
    </div>
    <!-- uncomment below to use with full screen popup -->
    <!-- <div class="background-mask"></div> -->
</div>
`