Sign in to an existing Helio merchant account using an external authentication method.
api.hel.io/v1 and generate API keys there. For the development environment, use api.dev.hel.io/v1 and generate API keys from moonpay.dev.hel.io.Contact the Helio team directly to obtain API keys.
The merchant-generated unique identifier used as a stable external reference for the account.
Returns user and company details along with a redirect URL.
The response is of type object.