Is it possible to pass the user name to the "Workers" REST API while creating Employee?

Summary:

Using /hcmRestApi/resources/11.13.18.05/workers REST API will create automatically an Application User formatted as FirstName.LastName or email Address (depending on the User Name Generation Rule). We need to pass the user name to the Workers REST API as we are using a specific format.

Content (required):

We are using Workers REST API to create Employees, and we need to pass the user name to the Workers REST API while creating the Employee as we use a specific format for the user names.

Is it possible to pass the user name to the Worker REST API? If not how to stop the API from creating the user automatically.