code: public static function encode($string)
      {
          if (strlen($string) == 0) {
              // Gives an empty string
  
              return '';
          }
  
          // Convert string to binary
          $binaryString = '';
  
          foreach (str_split($string) as $s) {
              // Return each character as an 8-bit binary string
              $binaryString .= sprintf('%08b', ord($s));
          }
  
          // Break into 5-bit chunks, then break that into an array
          $binaryArray = self::chunk($binaryString, 5);
  
          // Pad array to be divisible by 8
          while (count($binaryArray) % 8 !== 0) {
              $binaryArray[] = null;
          }
  
          $base32String = '';
  
          // Encode in base32
          foreach ($binaryArray as $bin) {
              $char = 32;
  
              if (!is_null($bin)) {
                  // Pad the binary strings
                  $bin = str_pad($bin, 5, 0, STR_PAD_RIGHT);
                  $char = bindec($bin);
              }
  
              // Base32 character
              $base32String .= self::$alphabet[$char];
          }
  
          return $base32String;
      }
docs: Encodes into base32
  
  @param string $string Clear text string
  @return string Base32 encoded string