I,R,S, FAX number in USA for Form 3911?

Hello: The I.R.S. mailed a check for EIP 2 to me, on  January 6, 2021.  It is lost in the mail. I need the FAX number in the USA, for the I.R.S., that I should send the Form 3911 to them on. Thank you for your time and your help!