Leave Box 1 "blank", i.e. don't enter a "0". You should not have to prepare an additional K-1 to report Box 1 income, if there wasn't any.
If you can't clear the "0" entry in Box 1, you may have to use the "Delete a Form" tool to
remove the Schedule K-1 (and any
associated worksheets).
See: How do I delete forms in TurboTax Online?
After deleting the Schedule K-1, log out of the
program. When you log back in, use the Delete a Form tool to confirm
the Schedule K-1 has been removed from the list of forms in your
return.