Select currency on Checkout – WooCommerce

Solution:

Had the exact same issue, the answer annoyingly is that you can only output Realmags currency changer on pages with a product in them. A very hacky solution is to include a product in your footer and hide it with CSS.

footer.php

<?php echo '<div class="hidden">'.do_shortcode('[product id="<ID OF YOUR PRODUCT HERE>"]').'</div>'; ?>

styles.css

.hidden {
  display:none;
}