You have up to three years from the due date of your return to amend or change something that was reported on your original return.  It is understandable that you want to get it taken care of as soon as possible.  However, due to the many changes in the tax laws that have been passed recently, the TurboTax program is still being updated.  

Take a look at the following TurboTax article for more information and click the link in the article to register your email address so that you will be notified when you can come back and amend your return:

Why can't I amend my return?

Just because I have three years to do it doesn’t mean I want to wait three years to receive my tax returns TurboTax is the only company right now that Cant amend returns everyone else can everyone I’ve spoken to doesn’t understand why just TurboTax can’t amend returns the IRS website can H&R Block can other people on Random sites can just turbotax and I keep getting told that I can’t amend my return on any other site because I filed on TurboTax but TurboTax thinks it’s cool to just screw us all 

TT can amend Federal returns now.  See this:

How do I amend my 2020 return? (intuit.com)

Just be aware that, when TT (or any software company) make a programming change, the IRS must approve it before it can be released.