Manually Track an Object with Keyframes
With a project open in Studio, add a trackable object. For example, a 3D disc.
Once the trackable object is on the video, move the orange playhead forward one frame. The easiest way to move between frames is to use the arrow keys on the keyboard. Once you have moved the playhead, click and drag the trackable tool (in this example, the disc) to the relevant position.
You will see white markers on the blue bar to indicate the frames where the player is tracked.
Follow the above steps with each following frame where you'd like to track the player.
Alternatively, enable automatic 3D tracking.