Rotating animation at the same speed

hello, So I have a circle that I want to rotate, I already animated it to go from 0 to -360 but the problem is that unity makes it smooth and so the animation picks up speed at the start being the fastest in middle and slow at the end. I tried making it linear, flat, broken but nothing worked, I also tried making it a straight line but this just stopped the whole animation, and trying to make the animation go down is basically impossible, so I ask how do I make an animation that rotates the item at same speed everywhere in the animation?