How do I get a testflight invitation code for my testflight app?

You can get those invitation codes from the app developer that you want to test. For example, if you want to test Microsoft Excel in TestFlight, then you would either get an invitation code from Microsoft or you would go to Microsoft’s website and find out how to test their product in TestFlight.

Axel F.

You need to get that from the app developer.

OK. This is an iPhone forum, not Test Flight customer support. This has nothing to do with Apple, so contact whoever the developer is for this.