According to our supplier, it is as follows: It is not really suitable for the iPhone 13 Pro, as the smartphone has a triple camera and so the attachment is not successful. Unfortunately, there is also no compatibility list. I think the lens was designed for the iPhone X at the time.

No.

According to https://www.ulanzi.com/products/75mm-macro-lens a universal clip (with a screw that can tighten the clip) should be included (as shown on picture 5).