How do you convert a folder of .wav audio into .mp4 video with a .png image file using ffmpeg in the command prompt?

Question

I have tried to do

ffmpeg for i in *.wav; do ffmpeg -loop 1 -i image.png -i "$i" "${i%.*}.mp4" -c:v libx264 -c:a aac -b:a 192k -shortest %04d.mp4

but it doesn't work and I am unsure of where to go from there.