Hi @teun
You can also get the URL instead of the embedded code by passing the format value to false like this:
<?php $instagram_url = get_field( 'instagram', false, false ); ?>
<img src="<?php echo $instagram_url; ?>media/?size=l" />
But the best way to get the image would be by using the API instead. This page should give you more idea about it: https://www.instagram.com/developer/endpoints/media/.
I hope this helps 🙂
