Was the audio too quiet on something that you recorded?
Are you lazy and you don’t want to drop in the file to a timeline editor just so you can gain boost?
most laptops will have ffmpeg on them, and if your mac doesnt then a simple brew install ffmpeg https://formulae.brew.sh/formula/ffmpeg
ffmpeg -i "your_input_file.mp4" -vcodec copy -filter:a "volume=15dB" "your_output_file.mp4"
there you have it short and simple now your video file is louder.