Explanation:

Box 1: Flow Checker
The Flow checker feature will promote higher quality flows by ensuring you follow best practices. By running the checker, you will be able to get answers to questions like: which areas of my flow implementation pose a performance or reliability risk?
For each issue identified, the Flow checker points to specific occurrences within the flow where improvements may be required. And more importantly, you learn how to implement these improvements by following detailed guidance.
Box 2: Test
Box 3: Test
Reference:
https://flow.microsoft.com/en-us/blog/flow-checker-four-connectors/
https://docs.microsoft.com/en-us/power-automate/modern-approvals