Invert drawing?

Mac OS - Attempting to copy the selected lines on the right side of the image - to the left side of the image (an inverse symmetrical copy - effectively a mirror function) - but I can’t find any funtionality to actually do this? I am new to shapr so go easy on me, I’m sure theres probably something easy i’m missing. Thanks guys.

Mirror tool is your friend. Just mirror the mirror? Choose your reference line carefully. Do it out of sketch mode.