According to german philosopher immanuel kant, what was the enlightenment's precondition?

I believe the answer is: freedom

According to kant, the precondition of enlightenment is to allow the people to pursue their own enlightenment by experiencing their life to the fullest.

This includes the the freedom to use their own intellect to pursue their interest (whether it's art, sciences, or psychical adventure) rather than have to conform to the set of thinking that imposed by the church and the government.