Edit the php.ini file, check/change extensions dir to where it is located. If PHP was installed through DSM it should be something like ‘/volume1/\@appstore/PHP7.0’ extension_dir = "/volume1/@appstore/PHP7.0/usr/local/lib/php70/modules/"
Enable the extensions you wish to use: extension = mysqli.so
extension = phar.so
extension = openssl.so
extension = zip.so
extension = curl.so