I need a copy of my last year's 1099 G form how can I get that?

Copies of a Form 1099 would have to obtained from the issuer of the form.  TurboTax will only have worksheets based on the information you entered from the Form 1099-G.

To access your prior year online tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/

Scroll down to the section Your tax returns & documents.  Click on the Year and Click on Download/print return (PDF)

If you used the desktop CD/Download editions installed on your computer, the only copy of your tax data file and any PDF's will be on the computer where the return was created.  TurboTax does not store online any returns completed using the desktop editions.

TurboTax does not have a copy of your 1099G.   The data you entered from it will be in the worksheets that are part of the pdf of your saved return, but there is not an image of the 1099G.    If you need an actual copy you should seek it on the state's unemployment website.

To get a copy of your previously filed returns prepared with online TurboTax https://ttlc.intuit.com/questions/1900748-how-do-i-get-a-copy-of-a-return-i-filed-in-turbotax-online