Indoor kitties usually stay close to home. Put something with your scent on it (unwashed clothes) outside as well as the kitties litter box. If you have any other cats or put something with there scent on it too. Check under your porch if you have one. Check under grills, sheds, in garages, sheds, basements. The cat could have gotten stuck in a neighbors shed. Check yours as well as. Go door to door and ask if anyone has seen her, even put flyers at peoples doors. Leave out bowls of stinky foods , such as mackerel or sardines and set a trap with worn piece of your clothing. If there are any abandon houses or for sale houses, with no one living in them check there. Also look around at night under bushes and in shrubs with a bright flashlight. It may catch on the kitties eyes. Looking at night when its quieter is better. If he went out the door leave it open might just come in on his own.you could also get a camera (Such as the Nest. They’re not too expensive). And to leave a window or door cracked open with food inside the house by that opening. They usually go to The same opening they escaped from.