If you want to disable pasting for a specific TextField you can use UITextFieldDelegate. Below code is working to find a specific TextField and stop pasting.
class TextClass: UITextFieldDelegate {
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if textField == yourSpecificTextFiled{
if UIPasteboard.general.isKind(of: UIPasteboard.self){
return false
}
return true
}
}
}