How to get privy-authorization-signature in iOS SDK for sponsor transaction?

[mehulFunnMedia1]

We are trying to send a sponsor transaction, and for that, it requires setting the privy-authorization-signature in the request header.

So far, we have successfully fetched the userKey using the following endpoint:
https://api.privy.io/v1/wallets/authenticate.

However, we are unable to find a way to generate or retrieve the privy-authorization-signature in the iOS SDK.

Questions:

1. Is there a method or utility in the iOS SDK to generate or retrieve the privy-authorization-signature?
2. If not, could you guide us on how this can be securely implemented in an iOS environment?

Any help or pointers would be greatly appreciated!