Subscription plan changed

Sent when a subscription moves to another price: through the API (POST /v2/subscriptions/{id}/change-plan) or the dashboard. Nothing is charged when the plan changes; the proration is added to, or credited on, the next renewal invoice. data.object carries subscription_id, customer_id, status, previous_status, previous_plan_name, new_plan_name, amount, currency, effective_date and action_source. For a change made through the API (action_source api), amount is the new renewal amount in minor units. Fetch the subscription for its current price and amount.