Snapshot Pose Function
An alternative way of using the Pose Snapshot feature is by calling the Snapshot Pose function within Blueprint to save a snapshot to a Pose Snapshot variable.
When using Snapshot Pose, you will need to provide a variable to save the snapshot to as shown above.
Inside your AnimGraph after adding the Pose Snapshot node, set the Mode to Snapshot Pin and check the (As pin) Snapshot option inside the Details panel.
This will expose a Pose Snapshot input pin on the node where you can pass in your desired snapshot variable.