curl --request POST \
  --url https://api.dualship.run/api/v1/billing/portal \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "return_url": "<string>",
  "workspace_id": "<string>"
}
'

{
  "url": "<string>"
}