Airflow Experimental Delete API not implemented for RBAC enabled Airflow.
There is a issue with Airflow where if RBAC for Webserver is enabled, the delete API from airflow was returning 404. On digging the airflow source code, it was discovered that there is separate handler for api requests with rbac enabled which doesn't provide delete API.
Github Source: endpoints when rbac enabled
So if we remove RBAC from webserver we get the Experimental delete API.