Tax Free Registration as Gov't Employ

As a federal employee, I should be able to register tax free. Zoom does not allow for this and thus I am not able to register for the professional conference that is currently ongoing. The purchasing agent requested this information on 4/19 and has not heard back. I tried using the chat feature and am currently waiting for customer support to pick up. The conference started at 9:00 am. I have been trying to resolve this issue from 8:00 am this morning 4/24.