My taxes for Lift are done but zi need to do taxes for Uber. I have an extension with the IRS but am ready to finish and pay. How do I do this?

Do you mean you filled out the schedule C for Lyft and need to add another schedule C for Uber?  Hopefully you didn't actually submit and file the Lyft return.  Or you need to Amend.

The uber and lyft income and expenses should have been put on one single Sch C on the same form 1040 ... they are NOT filed separately ... did you not mention this to the CPA you were working with ?