Following the documentation the curl must be this
curl -X GET "https://axa.dxi-na1.saas.broadcom.com/ess/notify/v1/channels/<tenant>/<channel id>" \
-H "Authorization: Bearer <token>"
where <channel id> is the channel id.
But it is not working. Please, could you confirm that this is the correct URL?
curl -X DELETE "https://axa.dxi-na1.saas.broadcom.com/notify/notify/v1/channels/<tenant>/<email channel id>" \-H "Authorization: Bearer <token>"
If you are using the UI to verify, please ensure you manually refresh the page.