First go to "Account and Billing" section under My Profile in the top right hand corner of your screen.

Then check the box next to "Activate Transcription Features".

Once the transcription features are enabled go to your case file and under the "Files" section in your tool bar select audio from the drop down box. 

Click the "Upload Audio" button to add the recorded interview to the case file. Once the file is loaded select the option on the far right of your audio file, the icon is a page with a microphone in the middle. This will transcribe the statement.