You do NOT include a copy of the original tax return when amending a tax return. The original tax return has already been received by the IRS. The original nor the amended Form 1040 are sent with the amended return. Only the Form 1040X and schedules and/or forms that were changed by amending are sent.
See this TurboTax support FAQ for amending a tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...
