Paysera payment integration

Could anybody help me and explain how to install paysera payment in opencart version 2.2.0.0?

Where (to which site catalog) do I need to upload paysera extention in my site and how to install it that I could see it in the admin panel payment list?

Thank you for the help.

Asta

I have such errors with paysera module:

Warning: require_once(/home2/looxmagc/public_html/maxdeal.lt/system/library/vendor/webtopay/libwebtopay/WebToPay.php): failed to open stream: No such file or directory in /home2/looxmagc/public_html/maxdeal.lt/admin/controller/payment/paysera.php on line 2
Fatal error: require_once(): Failed opening required '/home2/looxmagc/public_html/maxdeal.lt/system/library/vendor/webtopay/libwebtopay/WebToPay.php' (include_path='.:/opt/php55/lib/php') in /home2/looxmagc/public_html/maxdeal.lt/admin/controller/payment/paysera.php on line 2

What do I have to change?

Regards,
Asta