Can Cognito custom developer authenticated identities flow work with native apple login tokens instead of web apple login tokens?

Thank you for reaching out us regarding the above query. I would like to share that, Cognito does support developer authenticated identities flow work with native apple login tokens. In order to achieve the same, you can use Apple’s Authentication Services to launch a native Sign In With Apple flow, and federating into Cognito Identity Pools. You can utilise the below approaches to achieve your use case :

1. Amplify, via the escape hatch
2. SDK

The approach is such that, Cognito Identity Pools supports Sign In with Apple (SIWA) as an Identity Provider, meaning you can federate into your Identity Pool by using the native Sign In With Apple flow to obtain an ASAuthorizationAppleIDCredential identity token that you pass to Cognito. If the token is valid, Cognito will issue the client library AWS credentials that your app can use to access AWS resources. Please refer to the Github issue comment for more detailed explanation on this. Having said that, in case you face further challenges, please feel free to open a support case with AWS using the following link.