Create a Sales Order with Braintree payment method and invoice the same order by clicking on [Create Shipment], [Confirm Shipment] and [Prepare Invoice].
[Authorize CC payment] and [Captured CC payment] actions will be enabled if the record is not authorized at the Sales order /Process screens.
Authorize Action at Sales Order Screen
Click on the [Authorize CC payment] action and the transaction id can be found in [Proc. Center Auth. Nbr.”] column.
Authorize Action at Sales Order ScreenAuthorized Transaction on Braintree