How to Add Title to IMG tag on Single page?

This has actually been applied to core in the next release.

However for now, you can do something like this: https://gist.github.com/generatepress/14851417f7bcc7620737e2e22d2c2f98

The code you provided is just adding ALT tag, which I had already, but I wnated to add additional title tag.

I managed to do it by editing ALT to TITLE

add_filter('wp_get_attachment_image_attributes','tu_featured_image_alt', 10, 2);
function tu_featured_image_alt( $attr, $attachment ) {
remove_filter('wp_get_attachment_image_attributes','tu_featured_image_alt');
$attr['alt'] = $attachment->post_title;
return $attr;
}

changed to

add_filter('wp_get_attachment_image_attributes','tu_featured_image_alt', 10, 2);
function tu_featured_image_alt( $attr, $attachment ) {
remove_filter('wp_get_attachment_image_attributes','tu_featured_image_alt');
$attr['title'] = $attachment->post_title;
return $attr;
}

And it worked. Is this good solution? I am no develoepr so not sure! :)

Let me know!

That's a perfect solution :)