curl --request PUT \
  --url https://api.salesbricks.com/api/v2/subscriptions/{subscription_id}/payment-methods/default \
  --header 'Content-Type: application/json' \
  --header 'X-SALESBRICKS-KEY: <api-key>' \
  --data '
{
  "payment_method_id": "<string>"
}
'

{
  "subscription_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "default_payment_method_id": "<string>"
}