PMP Practice: Manage scope changes

Sky Okonkwo is managing a hybrid project at Cardamom Circuit Games to develop a cloud-based analytics platform. The predictive infrastructure workstream follows a detailed scope baseline, while the user interface is being developed using iterative sprints with evolving requirements. During a sprint review, the product owner approves several UI features that depend on backend API capabilities not included in the infrastructure scope baseline. The development team has already started implementing these features based on the product owner's approval. Infrastructure team members express concern that adding these APIs mid-project will delay their committed deliverables by three weeks. The product owner insists the features are essential for the minimum viable product and were always intended. What should Sky do to address this situation?