Animate > Set Blend Shape Target Weights Keys

Keys the target shape blend shape weights for the current blend shape deformation. When this menu item is selected, the following can occur:

If only the base shape is selected, all its target shape weights are keyed.
If only target shapes are selected, the weights of the selected target shapes are keyed.
If the base shape and target shapes are selected, only the weights of the selected target shapes are keyed.