Your tax return is the form you send to the government that shows your income and calculates your tax. The money the government sends back to you is your refund.
There is no such thing as a "return amount." Do you mean that you put your refund amount on the wrong line? Did you file your tax return with TurboTax? How could you put something on the wrong line if you used TurboTax? Did you fill out the forms by hand on paper?
What specifically did you put on the wrong line? What form and line did you put it on, and what form and line should it be on?
Did you already file the tax return (send it to the IRS) with the amount on the wrong line? If you did not file it yet, you do not amend it. You just fix the error in TurboTax before you file the tax return. Amending means filing a special form, Form 1040-X, to make a change or correction to a tax return that you already filed.