Which step is NOT mandatory when creating an API through Alibaba Cloud API Gateway?

When creating an API through Alibaba Cloud API Gateway, attaching a domain name is not a mandatory step. You can create an API without immediately linking it to a specific domain name, allowing flexibility in how the API is later utilized or deployed.

Defining the API endpoint, enabling API logging, and setting up request parameters are necessary steps to ensure that the API functions correctly, provides logging data for monitoring and troubleshooting, and handles inputs as expected. Each of these steps is essential for the API's functionality and usability. However, the domain name can be added later, which is why it is not considered a compulsory step in the initial API setup process.