Can't export audio

I am working with a wav file in Animate and am trying to export the video into a mp4 through Media Encoder. The audio never plays. All I hear is nothing. I tried every type of setting I could think of any nothing works. I tried just using audio from where it came from: a mp4 file I was referencing, but of course Animate just cannot export audio from mp4s when put into the Timeline. I tried using the audio from an FLV version of the mp4, but I need to render out the video from a frame other than Frame 1, and for some reason you cannot just edit a FLV in the Timeline??

Why can't I render out audio from Animate in an mp4?