curl --request POST \
  --url https://billing.funnelfox.com/{org_id}/v1/checkout/create_simple_client_session \
  --header 'Content-Type: application/json' \
  --data '
{
  "region": "<string>",
  "integration_type": "fakeintegration",
  "country_code": "<string>"
}
'

{
  "client_token": "<string>"
}