If you want to run your playtest on 2 platforms you'll need to start two orders. Specify the number of players you want per platform in the orders. For example, if you want 6 players in total, place two orders for 3 players each – one for iOS, one for Android
All you need to do is:
Make an order on the platform, being sure to give us: the build, the specified target device.
Go ahead and place the order, then return to the my playtests tab and find the order.
Once there, hit the duplicate order button and upload the second build in the duplicated playtest.
It’s as easy as that!