The End of Sprint Report consists of two-parts that describe:
How much of your sprint goal was met in terms of completed/validated PBIs. This part is called the Sprint Review, and essentially describes what you demonstrated to the Product Owner.
How your team performed in achieving that goal, and what can be done to improve in the future. This part is called the Sprint Retrospective, and is a post-mortem analysis of your sprint plan vs. actual effort, problems, effectiveness/amount of quality activities, and other things that happened during the sprint (both good and bad). The Retrospective is typically of less interest to the Product Owner than to the Scrum Master and the team itself; however, there can be situations where the Product Owner is interested, for example, in how the team will improve quality in future sprints.
Use the SE2800 End of Sprint Report template in Confluence, and follow the instructions found in the template.