TestFlight Deployment For Flutter App

I have a production-ready Flutter application that has already passed every Android test; now I need it live on TestFlight so I can distribute it to myself and a small private group of iOS testers. Because I work on Windows and do not have access to a Mac, I build through Codemagic. To protect my source, I will not share the code base. Instead, I will provide the exact build configuration, signing-related assets that belong to me, and any log or error message that surfaces during the process.

Here is the workflow I envision:

• You connect your paid Apple Developer account to Codemagic and handle all certificate and provisioning profile creation needed for an App Store Connect upload.
• Using only the settings I provide, you help me configure Codemagic so the iOS build succeeds and is automatically pushed to TestFlight.
• Once the build lands in TestFlight, you add me and my small tester group as internal testers so we can download and run the app.

Acceptance criteria
– The build compiles in Codemagic without code access.
– The binary appears in App Store Connect and becomes available on TestFlight.
– All invited testers (myself included) receive access and can install the app.

Prerequisites on your side
• Active, paid Apple Developer account you control (we will not use mine).
• Working paid Google Developer account, confirming you are fully set up on both major stores.
• Familiarity with Flutter iOS signing, Codemagic pipelines, and App Store Connect/TestFlight workflows.

If you have recently shipped Flutter apps to TestFlight using Codemagic, please mention that experience when you respond.