Write to support@morningstack.app and a real human (the same engineer who built the thing) will read it.
Morning Stack is $99/month, or $999/year. Both start with a 7-day free trial. Head back to the pricing section to start one.
Morning Stack is built and operated solo from Portland, Tennessee. There is no support phone number, no chat widget, and no help center yet. The product is small on purpose, and so is the company behind it.