code: public function protectCellsByColumnAndRow($columnIndex1, $row1, $columnIndex2, $row2, $password, $alreadyHashed = false)
      {
          $cellRange = Coordinate::stringFromColumnIndex($columnIndex1) . $row1 . ':' . Coordinate::stringFromColumnIndex($columnIndex2) . $row2;
  
          return $this->protectCells($cellRange, $password, $alreadyHashed);
      }
docs: Set protection on a cell range by using numeric cell coordinates.
  
  @param int $columnIndex1 Numeric column coordinate of the first cell
  @param int $row1 Numeric row coordinate of the first cell
  @param int $columnIndex2 Numeric column coordinate of the last cell
  @param int $row2 Numeric row coordinate of the last cell
  @param string $password Password to unlock the protection
  @param bool $alreadyHashed If the password has already been hashed, set this to true
  
  @return Worksheet