As of May 2022, it seems that the irs.gov login is broken. I've tried with different browsers (Firefox, Chrome). Always get the "Access Denied. You don't have permission to access "http://sa.www4.irs.gov/eauth/DasFcc/das.fcc" on this server." error message. I've been trying for over a week, so I guess they don't plan to fix this.
The workaround was to create a new ID.me account. You will have to upload your drivers license, face scan, and some other verification info. The IRS login was successful using the ID.me method, not the old login.
