curl --request POST \
  --url https://api.halth.com/v1/organisations/{organisationId}/clients/{clientId}/payment-methods \
  --header 'Content-Type: application/json' \
  --data '
{
  "confirmationTokenId": "<string>",
  "paymentMethodId": "<string>"
}
'

{
  "id": "<string>",
  "brand": "<string>",
  "last4": "<string>",
  "customerId": "<string>"
}