Including HTML Code to Exchange Textual content in PHP

I wish to change my obtain button for non logged in customers. As an alternative of the obtain button I wish to present a customized HTML code with message to login/register. The beneath code is hiding the button however the injection of the brand new HTML code will not be working.

<?php if (!is_user_logged_in()) : ?>
<model>
    .product-purchase-box{
        show: none;
    }
</model>
<script>
<p><a href="https://ezcliparts.com/login">LOGIN</a> OR <a href="https://ezcliparts.com/register">REGISTER</a> FOR FREE TO ACCESS THIS AND ALL 1 MILLION+ DESIGNS</p>
</script>
<?php endif; ?>

Goal Web page: ezcliparts.com/downloads/seamless-geometric-digital-paper-pattern-abstract-hand-drawn-background

Unique Obtain Button Output:

<div class="cart-box row product-purchase-box" model="user-select: auto;">
    <div class="col-md-12 paading-left-0 product-price" model="user-select: auto;">
        <h3 model="user-select: auto;"><span class="edd_price" id="edd_price_4701" model="user-select: auto;">$0.00</span></h3> </div>
    <div class="product_widget_inside" model="user-select: auto;"> <a href="#" class="edd-free-downloads-direct-download-link button white edd-submit" data-download-id="4701" model="user-select: auto;">Obtain</a> </div>
</div>

I created the web site with the assistance of a developer however the contract is over so I’ve to do it myself now.