After connecting to the vehicle, bouble click "Immobilizer", select "Utility", double click "Key Registration".
The rest is straight forward. It took me just one try because the keyless entry was already programmed with the pedal dance. Did you try a second time?
Now I supposed you already did all that? If so, try to check the type of user you selected in the configuration. I chose something like US Dealer. I heard some choices will not allow immobilizer programming.
Which version of Techstream are you using?