Made -w2 income, but also have 1099-nec income from 2 different states with the same employer

It depends.  First we will review the W-2s):

1. If you have W-2 income from the same employer for both states, in the federal entry put the proper amount in the state wage box for each state ('Add another state) line if necessary. Be sure to use the exact amount of withholdings for each state.  This number does not change.
2. If you have a W-2 for each state with different employers you can simply enter the W-2s as they appear with the correct state and state tax withholding.

The 1099-NEC or self employment income from Amazon Flex Driving:

1. You can divide the gross income for each state by the total gross income to arrive at the percentage of overall net profit that should be taxed to each state (unless  you have exact net profit for each state) then enter the amount that should or should not be taxed based on the questions in each state return.  
2. If you like create two schedule Cs, one for each state to separate the income, but this should not be necessary.

Review to make sure you are being taxed only on the income attributable to each state.

• How do I allocate (split) income for a part year state return?

You can view the tax summary for each state after you complete each part year state return:

On the menu bar on the left that shows. 

1. Select Tax Tools 
2. On the drop-down select Tools 
3. On the pop-up menu 
4. Select View Tax Summary (each state will be listed)