In order to add annotations to a screen, simply click the "Add annotation button" at the bottom, then click the location on the screen where you'd like to add the annotation.
You can also add an annotation by using ⌘ + Click (Ctrl for Windows and Linux users) anywhere on the screen and selecting “Annotation” from the top left menu.
💁♀️ Annotations support basic Markdown, making it easier to stylize and organize information.
When you create an annotation on a screen, you can link it to a component, as well. You can select an annotation type to describe the stage of the development, such as Behavior to explain how a specific element in a design should behave, Requirement to document technical product decisions, Animation to describe the specs of an animation, API to describe which API endpoints to use, or create any custom annotation type your team requires. The annotation types would help your teammates filter annotations and quickly get what they need.
You can learn more about how to manage annotation types here: Creating, editing, and managing annotation types.