How to file a 2018 amended return with schedule 1 in TurboTax Online? I have paid for the Deluxe version....

https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed?jump_to=answer_3288565

A 1040X cannot be e-filed.  It must be printed and mailed.  It will take about 3-4 months for the IRS to process an amended return.  It is a good idea to use a mailing service that will track it, like UPS or certified mail, so you will know it was received.

Wait about 3 weeks from mailing and you can check the status of your amended return:

https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1

https://www.irs.gov/filing/individuals/amended-returns-form-1040-x/amended-return-frequently-asked-questions

https://ttlc.intuit.com/questions/1908543-do-i-need-to-amend

https://ttlc.intuit.com/questions/2566895-what-does-it-mean-to-amend-a-return

If you completed and filed a 2018 tax return using the online editions, have received the tax refund or paid the taxes owed then you can start an amended tax return.  An amended return can only be printed, signed, dated and mailed by you, it cannot be e-filed.

See this TurboTax support FAQ for amending a 2018 tax return originally completed and filed using the online editions - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/01/27577