curl --request POST \
  --url https://billing.funnelfox.com/{org_id}/v1/checkout/one_click \
  --header 'Content-Type: application/json' \
  --data '
{
  "external_id": "<string>",
  "pp_ident": "<string>",
  "client_metadata": {}
}
'

{
  "action_required_token": "<string>",
  "checkout_status": "processing",
  "failed_message_for_user": "<string>",
  "order_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a"
}