Thanks for reaching out to us. You might get this error if you have not created any login policy for your application from miniOrange admin dashboard. Go to Policies> Add Policy from the miniOrange admin dashboard to create a policy for your app.
If you can let me know the account email you have used to create an account with us, we can check your configuration once and resolve this quickly. Please reply to email@example.com so that we can check your account logs and help you out quickly.