Customer Delete using REST Web API in Magento 2 comes with URL endpoint V1/customers/:customerId and DELETE Action.
You need to replace :customerId in the URL with the actual customer id.
You have to pass Header as Admin Token to delete customers in Magento.
EndPoint URL: <HOST_URL>/rest/V1/customers/:customerId
(Example, http://127.0.0.1/magento243/rest/V1/customers/3 Where 3 is the customer id to delete.)
Header: Authorization Bearer <Admin_TOKEN>
Click the link to retrieve Get Admin Token
Payload Body: empty
For B2B Magento 2 Company Module,
If the customer is assigned with Company Admin, You cant able to delete it using the given API.
It will throw an error, Cannot delete the company admin. The delete operation has been stopped. Please repeat the action for the other customers.
You need to unassign from the company admin and then you can try to delete that customer.