The app includes plans to provide dedicated Streaming VPN servers - known as Premium Plans. However, if you are an existing user, it is possible that you have a Basic plan active.
All you need to do is tap the Recover Purchase button at the bottom of the screen, which shows the plan within the app. It will identify your active subscription to adjust the app automatically.
When you have a Basic plan and try to access a streaming server, you will be presented with a screen to start your subscription to a Premium plan.