php - show custom fields data in next and previous link in wordpress

I am trying to show a advanced custom fields data in previous post link in wordpress. But The data is not showing also it breaks the html as well.

<div >
<?php
$prev_post = get_previous_post();


if($prev_post) {
  $prev_title = strip_tags(str_replace('"', '', $prev_post->post_title));
  echo "\t" . '<a rel="prev" href="' . get_permalink($prev_post->ID) . '" title="' . $prev_title. '" >
  <strong>

  <<< &quot;'. $prev_title . '&quot;

  </strong>
  <img src="'.the_field("girl_image").'" alt="'.the_title().'/>


  </a>' . "\n";
        }
?>
</div>
Copy code

In this code the "girl_img" field contains the URL of an image. I want to show the image based on the URL. But it is showing the URL itself instead of showing the image.