Pre-requisites:

• REST UI: This module provides a user-friendly interface to configure the REST module.
• Enable the following Web Services modules from the Extend section (/admin/modules) of your Drupal site:
• JSON:API
• REST UI
• RESTful Web Services
• Serialization

Enable API and Assign Methods:

• The first step is to enable the API and assign the methods and operations allowed for that API. This can be done using the REST UI module, or by directly modifying the Drupal config.
• Click on the Enable API button.
• To enable the API using the REST UI module, click the Configure button (as shown below).

• In our example, we need to enable the /entity/user API. To do this, click the Enable option in front of it.

• Since our goal is to create a user in Drupal, select the following configurations:
• Method: POST
• Format: JSON
• Authentication Provider: rest_api_authentication
• This allows the miniOrange API Authentication module to authenticate the API. Click the Save Configuration button to continue.