Immanuel Kant has argued for only one categorical imperative which is best known by his formulation: “Act only according to that maxim whereby you can, at the same time, will that it should become a universal law.”
The Kantian categorical imperative is a product of reason alone. Kant understood reason as the faculty that discerns and dictates universal laws. He has posited that if reason dictates a moral law, then that law will be capable of being universalized—it would necessarily dictate that you must act according to the universal law, or in accordance to the maxims which can be universalized.
With his categorical imperative, Kant is not preaching a moral law which may dictate your acts. He is giving you the freedom to make your own choices. He is saying that you can act according to your own reason, and that it is your task to figure out what the rule of your reason is. There is only one caveat—you can act only as you would expect others to act.