Suppose you created a new API but when you test it you are getting a 405 status response like this:
{ "type": "about:blank", "title": "Method Not Allowed", "status": 405, "instance": "http://127.0.0.1/api/customers" }
This most likely means you forgot to select at least one HTTP method:
If you are testing from a browser then you must enable the GET method. If you are using an API testing tool, then you can enable any HTTP method appropriate for the API.