flutter google_mlkit_digital_ink_recognition candidates scores always 0

Question

I am using google_mlkit_digital_ink_recognition in flutter to recognize the letter that user draws. it is working fine and the candidates are shown, but the problem is candidate.score is always 0.

code example:

 var _digitalInkRecognizer = DigitalInkRecognizer(languageCode: 'ar');

 final candidates = await _digitalInkRecognizer.recognize(_ink);
 candidates.forEach((element) {
        print(element.text+element.score.toString());
      });