pc or mac. pc c:\users\"user name"\downloads. however. some browsers have a default location that can be different. in that case you can try re-downloading it clicking on it in the browser to find the download folder.
still problems
You are asking from TT Live, for which you paid extra. Please contact a rep.
https://ttlc.intuit.com/community/expert-review/help/how-do-i-connect-with-a-tax-expert-in-turbotax-live/00/27282