After you file

What you needed to do was simply add another business for the other person.   Enter it like 2 separate businesses.  You need a schedule C for each person.   I have the Home & Business Desktop program also.  But if you already filed and it was accepted then now you have to amend.  You need to wait until the first original return is done processing (which will take a long time) and you get the first refund.  Then you can amend.

How to amend a 2020 return both online and desktop
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-return/01/27439

You add another business here,