Take another photo (front facing) the gang box. If you have neutral, in the back behind your wires in your pic then you will have a bundle of white wires going to one wire nut. this bundle will be where you will add your neutral wire.
Only if you have neutral wire will the smartswitch work.
Having pics showing different angles will be better if you need to contact @TheSmartestHouse to help you witj properly wiring the switch.
Take pics of the wiring of the switch in garage as well.