Very few people who ever applied for a job could truly say they knew every aspect of the position. And, if they do, every company has their own way of doing things. It takes flexibility and commitment to learning to make the best of the position.
Saying “it’s not my job” doesn’t cut it. Neither does shoving the work off on others or just doing the bare minimum.
The only way to get ahead is to push for ‘better’, in everything. It’s attributable to the Japenese philosophy of Kaizen – continuous improvement. Every piece of the process, no matter how small or big, should be improved upon with small ongoing improvements. It works for people too.