How to get the interfaceNr, in-endpointNr and out-endpointNr ?

[iKK001]

Ho do I get the interface that has in- and out-endpoints ?

I have problems knowing which of the interface to take from the _configuration?.interfaces array.

And also which one actually has in-endpoint AND out-endpoint ? And what the in-endpintNr and out-endpointNr actually is ?

With my device at hand, on a my Mac I was able to guess all the needed numbers by total chance.

But on my Windows-PC I am clueless.

How do I get the correct interfaceNr and its in-endpointNr and out-endpointNr so that the following two methods actually work ?

_usbDevice?.transferOut(outEndpointNr, data);

and

var usbInTransferResult = await _usbDevice!.transferIn(inEndpointNr, 64);