How to get Attachment Page Link

Hello,
I am trying to make a theme and I am trying to get an attachment image and its attachment page link. I do lots of searches and can’t find out the solution. I can only grab the image but not the attachment page link. Can anyone help me with that? Here is the code I found.

<?php echo get_the_post_thumbnail( $page->ID, 'thumbnail' ); ?>

With this, I can show the image but not the attachment page link. Because every image has its own attachment page link.

I am looking for this kind of link

<a href="https://mysite.com/my-post-title-comes-here/post-id/attachment-page" target="_blank"><?php echo get_the_post_thumbnail( $page->ID, 'thumbnail' ); ?></a>