How to "if ... sent msg .. Else don't . (Swift code with QR)"

I'm new on this and I'm trying to build an "if" with swift code . So I want to make a QR code and when it reads one specific number then my "if" works and text a msg to specific number . And if the number isn't it right then I will make an else command that will not sent the msg .

Everything is possible but I'm really new on this , so I really appreciate any kind of help .