Amending 2019 returns - why do I have to re-enter everything?

So I am trying to amend my 2019 returns because there was a small amount of business expense I forgot to deduct. Now, when I open TT and chose to amend (choosing "New return -> Amend 2019 return after it was already filed), I could not just add this small difference to my existing business income/expense section - it's completely blank, including my total income and other expenses.

 

Am I supposed to re-enter everything? That's a lot of work. Did I do anything wrong here?