API is an essential framework for ecommerce software, and even if you are only beginning working with Magento, you must have already heard of it. This article is an overview of what is Magento 2 Web API, the types of it and how to work with each of them.
To add a new column on admin customer group page we will use extension attributes, which are new to Magento 2. They extend default functionality and often use more complex data types than custom attributes. These attributes do not appear on the GUI. This method is simple to implement, however, it is suitable for version 2.2 and earlier ones. First I will explain to you the implementation for 2.2 and earlier versions, and then we’ll proceed to 2.3.