curl --request PATCH \
  --url https://api-v2.missioninbox.com/billing/update_subscription/ \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --data '{
  "price_id": "<string>",
  "billing_address": {}
}'

{
  "subscription_id": "<string>",
  "status": "<string>",
  "current_period_end": 123,
  "cancel_at_period_end": true,
  "message": "<string>"
}