render_php_js_url_image.php

PHP
=======
public function readImage()
  {
    header('Content-type: image/jpeg');
    echo file_get_contents("http://app1.susalud.gob.pe/registro/Home/GeneraCaptcha?accion=image");
  }
===================================================================================================
JS
=======
 function getCaptcha(url_image) {
      fetch(url_image)
        .then(response => response.blob())
        .then(images => {
          var reader = new window.FileReader();
          reader.readAsDataURL(images);
          reader.onload = function () {
            var imageDataUrl = reader.result;
            let imageElement = document.getElementById('image');
            imageElement.setAttribute("src", imageDataUrl);
          }
        })
    }

===================================================================================================
HTML
=======
<img id="image" alt="">