Since you've already filed, you won't be able to utilize the Uber discount UNLESS your return is rejected by the IRS. If that happens, it's as if you've never filed and you can start over.
In order to access an affiliate partner discount, you must access TurboTax via the partner's website. In your case, this would be through the Uber "dashboard". See the TurboTax FAQ below for more explanation.
https://ttlc.intuit.com/replies/7059813
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***