Thank you for allowing me to assist you, my name is Joe and I will be happy to assist you with your concern today.
There are different aftermarket apps if you have one loaded onto your iphone such as life 360, if not then there is a built in app called "find my iphone" this is found under settings>icloud>find my iphone located ON the iphone and you have to have it turned on. You can then log into your icloud account online and so long as the phone is on you can locate the area it is in in most cases. Other than that about all you can do is call it. In terms of not locating but locking you can choose to lock it and put a message on it again via find my iphone if it has been turned on.
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