An amended tax return, Form 1040X, can only be printed, signed, dated and mailed by you to the IRS, it cannot be e-filed. The IRS will take up to 4 months to process the amended tax return.
See this TurboTax support FAQ for amending a 2018 tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-a-return-in-turbotax/01/27579
Payment of federal taxes owed on an amended return can only be paid by check or money order included with the mailed amended tax return.
A federal tax refund on an amended tax return can only be sent as a check in the mail to the address on the amended tax return.