sm-j730f u3 Imei Repear issue.

1. Power on the phone.
2. Tap 7 times on 'Build number' in 'Settings'-'About phone' to enable 'Developer options',
go to 'Settings'-'Developer options' and enable 'USB debugging'.
3. Connect the phone to PC with USB cable, install drivers if needed.
4. Select device in ADB settings.
5. Fill values what you need to repair.
6. Press 'Repair' button.
7. Press 'Patch Certificate' if you have network problem after repairing.

Operation: Repair
Selected model: SM-J730F
Software version: 34.8

If you are looking for 'Repair Network' function then you should use 'Patch Certificate'

Waiting ADB device... OK
Reading phone info...
Model: SM-J730F
Android version: 7.0
PDA version: J730FXXU3ARI1
CSC version: J730FLUX3ARI1
Phone version: J730FXXU3BRI3
Product code: SM-J730FZSGLUX
CSC country code: Luxembourg
CSC sales code: LUX
Phone SN: R28K14CE13J
IMEI: 359605089764479
HW version: MP 0.400
RF cal date: 20180130
Chip name: EXYNOS7870
Modem board: SHANNON315
Security patch: 2018-09-01
Boot Warranty bit: 1
SIM State: ABSENT,ABSENT
Checking Super user right... true
Reading NV data... OK
Checking NV data... OK
Reading data... OK
Detecting MODEM... OK
Reading MODEM... OK
Calculating... OK
Writing zTool... OK
Initialization zTool... OK
Running zTool, please wait... OK
Reading data... error (1 13.3)
Initialization zTool... OK
Running zTool, please wait... OK
Reading data from phone... error (0)
Try downgrade modem if possible
Done with Samsung Tool PRO v.34.8