The QA Strategy is the plan for how you are going to approach project quality. Use it as your Agile framework, for business to maintain process of project initiation and reviews/reporting.
Quality Assurance can be applied from project conception through to delivery.
The development process is commonly overlooked in Agile application, as most effort is focussed on project management (with Scrum largely adopted).
There are many approaches to choose from, from the more project-agnostic Sprint planning method, to Lean software development approaches, such as Kanban and BDD (Behaviour-Driven Development).
And Acceptance Testing framework is what can deliver transparency to the team and to the business – and will keep the developers and testers on track. It will enable you to monitor progress from wherever you are, as well as updating requirements changes.