Authentication failed

[R0D30Sec]

Reproduction steps
Copied the environment file and added my own Test Stripe API keys.
Ran npm run dev
Clicked "Get started"
Clicked "New user? Create an account "
Chose "Create an account" instead of "Quickstart"
Provided username and password
Provided business name and chose default Business Details

JavaScript console returns the following error, and the UI for /onboarding route does not render the onboarding UI.
The fetchClientSecret function should always return the client_secret as a string. The function that was provided returned a different value type of undefined, so authentication will fail in this session.