How to Convert H4 Elements to Bold Text in Google Docs with Apps Script

function convertH4ToBoldedText() {
  var doc = DocumentApp.getActiveDocument();
  var body = doc.getBody();
  var searchType = DocumentApp.ParagraphHeading.HEADING4;
  var foundElements = body.getParagraphs();
  
  foundElements.forEach(function(element) {
    if (element.getHeading() === searchType) {
      // Change the heading to normal text
      element.setHeading(DocumentApp.ParagraphHeading.NORMAL);
      
      // Get the text range and apply bold formatting
      var textRange = element.editAsText();
      textRange.setBold(true);
    }
  });
}