The issue was as simple as removing the forward slash (although in the documentation example the forward slash exists) at he beginning like so:
$config['source_image'] = 'assets/images/tv-share.jpg'; $config['new_image'] = 'assets/images/tv-share-done.jpg'; $config['wm_overlay_path'] = 'assets/images/share_en.jpg';
what got me confused this error:
Your server does not support the GD function required to process this type of image.
I never thought it was only a path issue when I saw the error above.