They're working on it. 

"Rettig's comments come as the IRS prepares to start the tax filing season on Feb. 12, which is a later-than-usual start date.  During the filing season, people who did not receive the full amount of the stimulus payments to which they are entitled can claim a 'recovery rebate' tax credit. The IRS is working to ensure that its systems can verify that the rebate credits it provides to taxpayers are accurate."

https://thehill.com/policy/finance/535278-irs-chief-agency-is-current-on-mail-as-start-of-filing-sea...