how do I find my dog through his chip?

Microchips are not gps devices they give the chip number and a phone number or tell who the owner is, their address, and their phone number, but they don't help you locate your dog. That would require a vet or animal control officer to scan them and to maybe make a call to get your information and call you. It doesn't allow you to let them run loose or not to obey the leash law, You still have the legal responsibility to keep your dog leashed or confined to your home or a securely fenced in backyard so I suggest you get off your keester and get to looking little girl.

You don't.

Had you been constantly supervising, securely contained it when you couldn't it wouldn't be missing.

Start posting lost fliers, at all vet offices, shelters, rescues, pounds, around the neighborhood, in local newspapers and go out and look for it.

Should someone find it, they should scan the chip, and contact you.

His microchip has a number on it, which pops up when the chip is scanned - something that any rescue, vet or animal control officer would hopefully do when they found any dog. They can then look up the number on the chip in a data base maintained by the chip manufacturer - and up should pop your name address and phone number.

You can't unless he is brought in and scanned some place. Call your chip company and let them know the dog is missing and they will flag it to alert the next person that scans the chip.

You can't if you mean is the microchip a tracking device? If he's found, whoever scans him should be able to find you, so you can be reunited however.