You should be able to access that particular form inside of your TurboTax account. Please follow the instructions listed below for a step-by-step process on how to obtain your IT-255 form:
You will find the Form IT-255, Claim for Solar Energy System Equipment Credit, in your State Return.
To enter using TurboTax Online, please take the following steps:
1. Sign into TurboTax
Online
2. Continue your return by
click Taxes > Tax Timeline > Take me to my return.
3. Click on the State Taxes tab (make sure your federal tax return is completed before starting your state taxes)
4. Start your State Return
5. Continue through the interview until you get to the page titled, "Take a look at your (states) credits and taxes."
6. Scroll down to the Your Home section and click Start next to Installed Solar Energy Equipment in 2016. (screenshot attached)
7. This will start the interview process to fill out
Form IT-255.