Make a keyframe
When you create a keyframe, you record the value of a property at a specific point in time. By setting several keyframes on the same property over time, you are animating the property. You can change the property by setting values in the Properties panel, or by using the Selection tool or Subselection tool to move the object on the artboard.
Some properties cannot be animated. For example, you cannot animate the properties under Text in the Properties panel except for the FontSize property. If you animate the FontSize property, you must set the property for the whole object (in other words, you cannot animate the FontSize property when you are in text-editing mode). Additionally, if a property value references a resource, or is set to Auto, then you cannot animate it. Auto is a special, dynamically-calculated value. Because of this, you cannot record Auto as the value of a keyframe.
To make a keyframe
Select the timeline from the Storyboard picker by clicking the Open a Storyboard button under Objects and Timeline and then selecting a storyboard. If you do not yet have a timeline created, you can click the New button to create one.
Move the playhead to the desired point in time.
To make a keyframe, use one of the following methods:
Click the Record Keyframe button .
A keyframe is created on the timeline for the selected object. The keyframe will store any property changes that you make when the playhead is at this point on the timeline.
Modify an object on the artboard by setting a property in the Properties panel or by modifying the object by using your pointer.
A keyframe is automatically created on the timeline. The keyframe records the property changes that you just made.
Always move the playhead and then make the property change.