I tried this command to overlay a background video with audio under a green screen vid. However, I keep on loosing audio. How do I keep the audio?

also, green screen leaves some green at the edges behind. any idea how to optimize that?

ffmpeg -i main-1.mp4 -i green.mp4 -filter_complex "[1:v]chromakey=0x00FF00:0.18:0.01 [ckout];[0:v][ckout]overlay=eof_action=pass[out]" -map [out] output.mp4