Pretty girls tend to avoid me, and I struggle with how to approach them—how do I build confidence to keep trying?

I've noticed that pretty girls tend to avoid me, and I admit, I sometimes struggle with how to approach them. I often wait for the right moment when they're alone, hoping for the best opportunity to talk to them. But even when I'm not trying to approach them or show interest, they still avoid me. I've never experienced this with women I'm not attracted to or older women. I really want to approach them, regardless of whether I get rejected, but I never seem to get the chance. It affects my confidence, and I'm not sure how to keep moving forward. Any advice on how to handle this?