In getting https://github.com/paypal/merchant-sdk-ruby to work with Padrino, I need an app id
...
app_id: APP-80W284485P519543T
....
but within PayPal, I can only find where to create sandbox accounts but not apps. The only option seems to be an official "new app" request, with details that aren't really that relevant for testing purposes.
Do I have to submit this info even before beginning to implement functionality in the app I'm developing?