https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online/00/26258
Or....are you using desktop software? Do you want to mail the state return to avoid the $25 state e-file fee? Tell the software you do not want to e-file state. Then go to the top left of your computer screen to File---you will get a drop down that lets you choose which return to print--choose the state return and print it for mailing. Make sure you also save the return as a pdf and as a tax file.