Despite features showing as grayed-out Yes in admin, they might not actually be enabled. Make sure the Use Website checkbox is unticked and proper value is selected.
While debugging the application the testing account is required. You can create a free Yotpo account here. You will also need to set up Ngrok, because Yotpo API has a CORS policy, accepting new reviews only from select domains. Please use the --host-header=rewrite if running it with React App (instead of Magento 2).
Extension is implemented using functional components. Yotpo is rendered using native widgets.