Custom link

Alright, so as the title says I want to be able to have a custom link in this widget, but the image I have is only a .png file on my computer. I tried creating a new folder and use custom icons with a fullpath.php file `<?php
$dir = dirname(__FILE__);
echo “<p>Full path to this dir: ” . $dir . “</p>”;
echo “<p>Full path to a .htpasswd file in this dir: ” . $dir . “/.htpasswd” . “</p>”;
?>`to find the path for the image. However, using this I am sent to a page saying 403: Forbidden. so what am I doing wrong? Any suggestions?

https://wordpress.org/plugins/social-media-widget/