I'm creating a wordpress theme and am having trouble generating a video link to go into an iframe source. I've tried troubleshooting and it seems that the issue is beyond wordpress and I can't actually input any link with PHP to work with iframe. Here's an example for simplicity's sake.
<iframe src="<?php echo 'https://vimeo.com/159120552'; ?>" width="640" height="360" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
The PHP works as far as I can tell (when I inspect it, the link is in the correct place), but there appears to be a blank web document created in the iframe instead.
Am I doing something wrong or is this a known issue of iframe and PHP?