What do you mean? Form 1040 is the basic tax document for everyone( Form 1040 U.S. Individual Income Tax.) This is part of every tax return.
TurboTax automatically creates and adds Form 1040 when you do your tax return. You can preview your 1040 before you file it. See How do I preview my TurboTax Online return before filing?
You'll need to file form 1040 if you meet the IRS filing requirements. See Do I have to file a trust tax return?