Why does the direction of angular velocity keep unchanged in uniform circular motion? Where is the direction? How to determine?

Why does the direction of angular velocity keep unchanged in uniform circular motion? Where is the direction? How to determine?

Angular velocity is a vector (more accurately, pseudo vector) that describes the rotation angle and direction of an object in unit time when it rotates in physics. It is usually expressed by the Greek letter Ω or ω. An object can have different axes in rotation. Just like the rotation axis of a ball, it can be any diameter of the ball