code: private function writeDefaultRowHeight()
      {
          $defaultRowHeight = $this->phpSheet->getDefaultRowDimension()->getRowHeight();
  
          if ($defaultRowHeight < 0) {
              return;
          }
  
          // convert to twips
          $defaultRowHeight = (int) 20 * $defaultRowHeight;
  
          $record = 0x0225; // Record identifier
          $length = 0x0004; // Number of bytes to follow
  
          $header = pack('vv', $record, $length);
          $data = pack('vv', 1, $defaultRowHeight);
          $this->append($header . $data);
      }
docs: Write BIFF record DEFAULTROWHEIGHT.