@BetterWP a workaround for now till we update our base image is :
In web terminal:
mkdir -p /app/data/jpegoptim
cd /app/data/jpegoptim
wget https://github.com/tjko/jpegoptim/releases/download/v1.5.5/jpegoptim-1.5.5-x64-linux.zip
unzip jpegoptim-1.5.5-x64-linux.zip
chmod +x jpegoptim
./jpegoptim --help