Open the Find My app on another Apple device
Sign in with the same Apple ID used on your iPhone
Tap Devices
Select your iPhone from the list
Tap Play Sound to locate it nearby
Tap Directions to open Maps for directions
Tap Mark As Lost to lock it and display a message with a contact number
Use iCloud.com/find on a computer
Sign in with your Apple ID
Select your iPhone on the map
Use Play Sound, Directions, or Mark As Lost from the options shown