Swift Localization: String String interpolation

Question

I am trying to add multilanguage support to my app. I am doing this by replacing all my User visible Strings with localized strings. For strings like "Cancel", this is easy. But I have just as many strings that are interpolated with information. And the hard part is that each language would build the sentence differently.

For example: How would I localize the following String: "Please enter the 4-digit Code sent to you at (user.PhoneNumber)"

In German, I want the string to look like this: "Bitte gebe den 4-Ziffer Code ein, den wir dir an (user.PhoneNumber) gesendet haben"

Or in French: "Entrez le code à 4 chiffres qui vous a été envoyé à (user.PhoneNumber)"

I am trying to find a way to use some kind of variable inside of my localization file like this (I know that this does not work):

Inside my ViewController:

title.text = "Please enter the 4-digit Code sent to you at %phoneNumber%".localized

Inside my Localizable.string

"Please enter the 4-digit Code sent to you at %phoneNumber%" = "Bitte gebe den 4-Ziffer Code ein, den wir dir an %phoneNumber% gesendet haben"

What's the best practice to do this? This must be some common issue people are having. Languages are so different!