WordPress Add a Post Type Confirmation message after Submit Button Click

document.addEventListener('DOMContentLoaded', function() { 
            var publishButton = document.getElementById('publish');
            var confirmed = false; // Status variable to prevent multiple confirmations
            if (publishButton !== null) {
                publishButton.addEventListener('click', function(event) { 
     if (confirmed) return; 
                    var postFormat = document.querySelector('input[name="post_format"]:checked').value;
           //var body_content =document.getElementById('content').value;
     if (tinymce.activeEditor != null) {
            var body_content = tinymce.activeEditor.getContent(); //check tincyMCE body
     }else{
             var body_content =document.getElementById('content').value;
     }
     //var pattern = /\bcaption\b/i; // Pattern to match the word "caption" (case-insensitive)
     var pattern = /\[caption/g; // Matches all occurrences of "[caption"
     //alert(body_content);
     //alert(postFormat);
                    if (postFormat === '0') {
                        confirmationMessage = 'Are you confirm?you choose "news" format?';
                    } else if (postFormat === 'gallery') {
             if (!body_content.match(pattern)) {
       alert("Please select the appropriate story format, as no images have been included in the body content for the chosen Gallery format.");
       event.preventDefault(); // Prevent default form submission
       return false;
      }
      confirmationMessage = 'Are you confirm?you choose "gallery" format?';
                     }else if (postFormat === 'quote') {
      if (!body_content.match(pattern)) {
       alert("Please select the appropriate story format, as no images have been included in the body content for the chosen Gallery format.");
       event.preventDefault(); // Prevent default form submission
       return false;
      }
                        confirmationMessage = 'Are you confirm?you choose "photo story" format?';
                    }  else if (postFormat === 'video') {
                        confirmationMessage = 'are you confirm?you choose "video" format?';
                    } else if (postFormat === 'link') {
                        confirmationMessage = 'Are you confirm?you link "link" format?';
                    }else if (postFormat === 'audio') {
                        confirmationMessage = 'Are you confirm?you link "audio" format?';
                    }else if (postFormat === 'aside') {
                        confirmationMessage = 'Are you confirm?you link "blog" format?';
                    } else {
                        confirmationMessage = 'Are you confirm?you choose "blog" format?';
                    }
                                         if (confirm(confirmationMessage)) {
                        // Proceed with publishing
                        confirmed = true; 
                    } else {
                        event.preventDefault(); // Prevent default form submission
                    }
                });
            }
         });