Beginner needs help exporting H.264 video with WAV/ Linear PCM audio

Hi all,

Sorry, this probably has a very easy solution but I'm completely new to compressor and can't find an answer anywhere else.

I'm trying to export a music video from FCPX and am hoping to get it to a H.264 video format with an uncompressed audio file. The audio is currently WAV but I understand it should be converted to LPCM. I set up the custom setting "H.264 for Apple Devices" but can't modify the audio settings to a different format.

Could some kind soul help me solve this? You'll have my eternal gratitude!