What form do I manually enter the information about the long term capital gain? The sale of the business was not recorded on any govt. form.
If you know the basis in the business (which in your case will be $0), the sales price and that it is a long-term capital gain, then you can just report this as the sale of a capital asset.
To enter the sale of a capital asset in TurboTax, log into your tax return (for TurboTax Online sign-in, click Here and click on "Take me to my return") type "investment sales" in the search bar then select "jump to investment sales". TurboTax will guide you in entering this information.