I recommend installing the free demo version right before acquiring and check the need for session management. The OC Session Manager module is mainly meant for OpenCart 3. Opencart stores some person info (language, currency, cart, and so on.) in PHP sessions. OpenCart can store this facts in two strategies: https://chancevurmj.theobloggers.com/38010943/the-definitive-guide-to-opencart-google-analytics-4