To create or remove records using POSTMAN ie with the use of API's you must first create a controller to make the api call to.
Like lets say you create a controller function for url '/create/customer' and in that function you accept the arguements from the api as json data which can be used to create customers into the database using orm methods or sql queries.
To drop a customer similarly you create another controller function in which you pass in the customer id or a unique identity with which the user can be identified and in the controller function you write the script to remove the customer.
For reference: https://stackoverflow.com/questions/65311574/odoo-controller-create-record-into-database
Hi muhammed emin,
Refer to know how to Authenticate, Fetch Data & Create Records in Odoo from Postman ,
Hope it helps,