If you want to make a particular quiz as paid, for example if you want to create a certification exam for lets say $10, you can now do that using this QSM addon. Payment Integration is a dead simple payment plugin for QSM (quiz and survey master) which enables anyone to pay for a quiz. You can set various options for Paypal and/or Stripe in the Addon Settings menu including Paypal email address and Stripe API keys. You can also enable Sandbox mode for testing.