code: public function getSignature()
      {
          $hashParts = [
              strtoupper($this->getUserId()),
              strtoupper(hash('sha512', $this->getPassword())),
              strtoupper($this->getTime())
          ];
  
          return strtoupper(hash('sha512', implode('', $hashParts)));
      }
docs: Get signature
  @return string