I believe this can only be done through a function or variable created manually under the kinematic body's node.
Modify your input code so that the body only takes inputs when another variable is true.
The way I structure my projects s to have a function handle all the inputs on the player, so I would just adjust the code under physicsprocess so look like:
if controllable:
get_input()
Then if in the animation player you change the variable controllable between true and false, you should be able to add or remove control from the player, while also letting the rest of the necessary scripts run.