readfile echo file_get_contents does not load content

[smile]

Hello, I use tooltip plugin https://github.com/object505/tipso

I use ajax tooltip.

I created content.php and in it I use full URL format like http://www.domain.com in the ajaxContentUrl

//Ajax

jQuery('.ajax1').tipso({

background: '#666666',

useTitle: '',

ajaxContentUrl : 'http://www.domain.com/ajax.html'

ajaxContentBuffer : 5000

 

But the tooltip with ajax content html page with image does not show if I access the page with the

<?php readfile("http://www.domain.com/content.php"); ?>

I get no error in the network tab in dev inspector, but the image file is never loaded and shown. If i load same page direct in browser everything works fine. Only the readfile method does not work.

I need a way to load the tipso from my remote site.