Get current step or initialize a flow

This endpoint returns the current step when the x-hf-session header is present and initiates a new workflow when it isn't.

Path parameters in the header must include the flowId which identifies the workflow.

Optional parameters can also include: x-hf-session and x-hf-language in the header. The x-hf-session is the UUID for the user state within that workflow, and x-hf-language is the language for execution of the workflow.