See https://ttlc.intuit.com/community/income/help/how-do-i-allocate-split-income-for-a-part-year-state-r...
I'm not familiar with the IA software, but, in general, you allocate income, by state, at the allocation screens, in the state software. The possible exception is that W-2 income is allocated at the W-2 screen (in the federal section) by the state abbreviation in box/line 15.
