Letter from IRS

Hi I work at H&R Block as a Customer Service Rep and one of tax pros clients received a letter from the IRS asking for more information for his 2022 Amended return and it asked for us to fax it but it does not provide a Fax Number at all in the letter and I went on the site searching for this letter head and there was nothing and I also googled nothing of the sorts came up. Could it be a Fraudulent letter?

 

Inquiring minds would like to know