Why does my API return a 405 Method Not Allowed status?

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.