How using delete "/pages/{page_id}/leads/{lead_id}" API

About this https://developer.unbounce.com/api_reference/#id_pages__page_id__leads__lead_id_ api

/pages/{page_id}/leads/{lead_id}

Delete a single Lead. Only available to the account owner.

NOTE: this endpoint cannot be used with API keys (OAuth only)

How to using this api step by step.
as i understand i must register OAuth Application right?
and system will send client id , client secret back to me .
and i will using this api https://api.unbounce.com/oauth/authorize?response_type=code&client_id=CLIENT_ID&redirect_uri=URL_ENCODED_CLIENT_REDIRECT_URI for get OAuth Token right?
and using this token on header this delete “/pages/{page_id}/leads/{lead_id}” API right?

It seems like that’s what I understand.

The problem with this flow that my company is facing is that it seems not to be possible to delete users based on ids assigned within my own company db – we didn’t bother to store a way to map a user to a lead_id in unbounce’s system.

Is there upcoming support for delete by email address?