Export Clip Transcription in JSX Script

how can I export transcription of a clip in JSX script?  Tried something like this but doesn't seem to the transcription.  I tried something like this,  also where is the documentation?  I found old links that don't work anymore. thank 

// Function to extract the transcript from a clip
function extractTranscript(clip) {
  try {
     var metadata = clip.getProjectMetadata(); // Retrieve metadata for the clip
     if (metadata) {
         // Look for specific metadata fields that may store transcript data
         var transcriptField = metadata.getMetadataField("transcript"); // Adjust field name if needed
         if (transcriptField && transcriptField.value) {
            return transcriptField.value; // Return the transcript text
         }
     }
   } catch (e) {
            $.writeln("Error extracting transcript for clip: " + clip.name + " - " + e.message);
        }
        return null; // Return null if no transcript is found
    }