Managed to add two Focus keys with original SuperOBD SKP900 key programmer. Share my experience with you all.
Preparation:
check the connection with the car and skp900 key programmer
Start skp-900
Insert the key and turn ignition on
Step 1 Delete keys
->IMMOBILIZER

->FORD

->FOCUS

->IMMOBILIZER2

LOADING…
->IMMOBILIZER SYSTEM

->CHOOSE OBDII ADAPTER

TURN IGNITION ON

->COMMUNICATING…
->DELETE KEY

->IT WILL DELETE ALL REGISTERED KEYS.
ADD MINIMUM 2 KEYS SO AS TO START ENGINE

->PROGRAMMING…
->NUMBER OF KEYS: 2

->PROGRAMMING…
->NUMBER OF KEYS: 0

->DELETE SUCCEED

Step 2 Add new keys
TAKE OUT THE KEY
TURN IGNITION OFF

->ADD KEY

->INSERT A NEW KEY

TURN IGNITION ON
->PROGRAMMING…
->NUMBER OF KEYS: 0

->PROGRAMMING…
->NUMBER OF KEYS: 1

->PROGRAMMING SUCCEED

The same way to add another key
->NUMBER OF KEYS: 2

Step 3 Test keys
Test the two keys newly added
They’re WORKING!

Done! Ford Focus new key programming succeed! Unplug the skp900 auto key programmer.