code: public function getFieldConfiguration()
      {
          $min = ($this->getSetting('MinLength')) ? $this->getSetting('MinLength') : '';
          $max = ($this->getSetting('MaxLength')) ? $this->getSetting('MaxLength') : '';
  
          $rows = ($this->getSetting('Rows')) ? $this->getSetting('Rows') : '1';
  
          return [
              $learnMoreField = FieldGroup::create(
                  _t('Moo_EditableFieldText.TEXTLENGTH', 'Text length'),
                  new NumericField($this->getSettingName('MinLength'), 'Min', $min),
                  new NumericField($this->getSettingName('MaxLength'), 'Max', $max)
              ),
              new NumericField($this->getSettingName('Rows'), _t('Moo_EditableFieldText.NUMBERROWS', 'Number of rows'), $rows),
          ];
      }
docs: Get extra configuration fields.
  
  @return array