This phoe can be unlocked with unique original MSL code only!
1. Phone must be powered on.
2. Type *#0808# and select 'DM+ACM+ADB'.
3. Run dialer and type *#0*# (service mode will apear).
4. Connect phone to USB cable, choose correct COM port in port settings.
5. Press 'Unlock' button.
6. Paste MSL code in new opened window and press 'OK'.

Operation: Unlock
Selected model: SM-A720F
Software version: 28.2

Searching Samsung modem... detected COM1085
Reading phone info... Ok
Model: SM-G955FD
AP version: G955FXXU1AQDG
CSC version: G955FOXM1AQDG
CP version: G955FXXU1AQDG
Product code: SMA
Phone SN: R58J538A42Y
Unique number: CE0417143BD1D4170C
Reading IMEI... Ok
IMEI: 35435908854chicago
Reading SN... Ok
Phone SN: R58J538A42
Enter MSL: 5A354E323F0C38504220044C2022bulls
Bypass MSL... Ok
Unlocking... Ok
Codes set to 00000000
Rebooting phone... Ok
Unlock done
Done with Samsung Tool PRO v.28.2