It says my 2021 return is rejected, and before whenever I worked on it, it said all good. Is there anything I can do about it now?

If the IRS rejected the return for some reason you were supposed to come back, make the needed correction and refile the return.   Now all you can do is print, ink sign and mail in the return. 

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

Expect a long wait---it is taking six to nine months for the IRS to process mailed returns.   Until a human opens the envelope and enters the information in the system, you will not see anything on the IRS refund site.