Only when you file your tax return.  The IRS won't start taking efiles until Jan 27, 2021 or later.

No ... it is NOT a fluid situation.   The only time the IRS gets the info you enter in the TT system is when you efile and the IRS accepts the tax return for processing.  

If this has to do with the stimulus check all you can do now it put in a forwarding address with the post office if allowed.