Background:  I have two short period 1041's to file and the 2021 tax forms are not issued yet.  The IRS says to use the 2020 Forms and note the short 2021 period on the top of page 1. 

So ... two questions:

1 - As I will be filing using a 2020 form ... I assume I prepare the return using the 2020 software and adjusting the dates, etc as advised.  Is this correct ?

2 - If I already filed a 2020 return for the calendar year ...  Based on my approach in question 1 above, How do I set up a second 2020 return in Lacerte to prepare the 2021 short period ?  

All assistance welcomed.  Thanks so much.