Hello,
Im not sure if this is the correct Topic but since I helped another Stencyl member with uploading a build to External Tester I thought that maybe another member would like this info. I will show you how I´ve done this with my App Pipe Monsters.
https://apps.apple.com/us/app/pipe-monsters/id1612245205See attached picture and added info below.
1, From Stencyl, publish -> Mobile -> IOS.
When asked for choose "for test" or something like that.
2, I think in total there is 3 ways of uploading your build to App Store Connect. Im using the app For Mac - "Transporter" (free).
Sign in using you Apple Id and the press the "+" and choose the build you´ve just exported.
3, After a few minutes you will hopefully see "Deliver" or something. press it and it will take a few more minutes to upload. If everything goes well it will say "successfully uploaded".
4, Then go to App Store connect and log in. choose your app and then "Test Flight"
5, Then If you see "External testing" press the "+". But if not, its probably cause you need to create an "Internal group" first. So create an internal group, it can be with just you inside it. If you would like to add more people (like family or close friends) you can do that from "Users and Access". Otherwise keep it with just you.
Hopefully you can now create an External Group.
6, Add some testers to your External Group.
7, When you have added some testers you can scroll down to "Add Build" hopefully you can see your build with "Ready to Submit" then you can just choose it. If its says "Processing" just wait 5-10 minutes and try again.
8, Last step - add for review -> Then the build will change to "waiting for review" and this will take 2-48h. Everytime you submit a build to external testers it need to be reviewed by apple, but after your first accepted build everytime you add a new build for Internal test it will be accepted directly.
I hope this will help you, and let me know if you need some help!