Integrate Paypal/Braintree into iOS app and configure server backend

Project specification I will provide an empty iOS app available via github. I will also provide whatever details you need from the test Braintree account. Please only use Braintree libraries when coding. Using this app I require the following to be added: Client side integration using Braintree. The app will allow the user to purchase a single item. Call the item ‘Product 1’ and have the value £10. When the user selects ‘PAY’ they will be presented with the Braintree Dropin UI where they can pay with PayPal, Apple pay or Credit Card. Once they pay they will receive a confirmation that the payment as successful. Server side – configure server side so the client can connect so to perform the transaction above. Please use Client Token (not Tokenization Key) for authorization. We can check the transactions are successful in the sandbox using the test account. Then I will also need some notes on what to do when I want to make it work with my real account in production. I would like to host the server side on Heroku. So I need a document with the steps on how to load the server side code you create, onto Heroku. I will perform this before we test the functionality of the app so that we can add in the Heroku address to the client code if needed. I also require documentation explaining each step above so I can replicate it for my main app.