Use Samsung Find My Mobile: https://findmymobile.samsung.com
Sign in with the Samsung account linked to the lost phone
Select the lost device from the list
Check the phone’s current or last known location
Ring the phone to help find it nearby
Lock the phone remotely to protect your data
Display a message and contact number on the lock screen
Back up data if the phone is still online
Erase the phone remotely if recovery is not possible
Use Google Find My Device: https://www.google.com/android/find
Sign in with the Google account on the phone
Locate, ring, lock, or erase the device
Check location history in Google Maps Timeline if enabled
Contact your mobile carrier to suspend service and block the SIM
Report the phone as lost or stolen to the police
Use the phone’s IMEI number for carrier or police reports
Change passwords for Samsung, Google, email, banking, and social accounts
Monitor accounts for suspicious activity
Keep location services, Wi-Fi, and mobile data enabled for better tracking
Make sure remote controls were enabled before the phone was lost