Where did you do the original return? Did you use Turbo Tax? You need to use the 2019 Desktop program to amend. Sorry you can't upload or use a printed or pdf copy.
For prior years you have to buy the Desktop program. You can only buy the download for prior years. You have to buy a separate program for each year. They only sell the last 3 years. You need a full Windows or Mac computer to install it on. Buy the download here
If you don't have the original.tax file you have to first recreate the actual wrong original return. You can use the Forms Mode. Then when it matches each line that you really filed you have to tell Turbo Tax you will mail it so it thinks it was filed. Then you can amend it.
How to amend a Desktop return,
There are 10 different options thru the IRS FREE FILE link so don't knock the all the options because you had a bad experience with one DIY program. And unfortunately once the online season has closed you cannot usually use it to amend the returns later. If you had used the TT option that would be an exception.