I'm trying to e-file a 2021 1040-X and keep getting this error.  I have a 1040-X in the return so I'm not sure what I'm doing wrong.  Any help is appreciated!  Thanks!

Return Rejected 01/26/2023
Code: IND-463
Form: 0(00) Form Copy:
Line #:
Description: X(/efile:Return/efile:ReturnData/efile:IRS1040/efile:AmendedReturnInd)
Error Detail:
If [ 'AmendedReturnInd' or 'SupersdedReturnInd' ] in the return is checked, then Form 1040-X must be present in the return.
Error Resolution:
Please review the reason for the reject. If necessary make the appropriate change and re-submit this return electronically. However, if the reject continues you may want to file this return via U.S. Mail, print this federal return and mail it to the appropriate IRS Service Center.