activation problems in WP

Hi.

I installe  the h5p plugin ( automatic install in WP admin), but when I try to activate it, I get the following error:

Parse error: syntax error, unexpected T_FUNCTION in /home/www/0121b250f6e36769b12c11376e25e1b0/web/wp-content/plugins/h5p/h5p-php-library/h5p-default-storage.class.php on line 180

The code is

             function ($matches) use ($cssRelPath) {
                  if (preg_match("/^(data:|([a-z0-9]+:)?\/)/i", $matches[1]) === 1) {
                    return $matches[0]; // Not relative, skip
                  }
                  return 'url("../' . $cssRelPath . $matches[1] . '")';

Any idea what could be going wrong ( I don't know php...)

Thank you in advance