Add baselineOffset attribute for superscript.
let mAtrString = NSMutableAttributedString(string: "*주의: 조심하자.")
mAtrString.addAttributes([.font : UIFont.systemFont(ofSize: 15),
.foregroundColor : UIColor.red,
.baselineOffset : 5], range: NSMakeRange(0, 1))
let label = UILabel(frame: view.bounds)
view.addSubview(label)
label.attributedText = mAtrString
