How to pick a specialization [duplicate]

Solution 1:

What you're missing is probably one or several of the strongholds. Have a look below.

In order to unlock Specializations in The Division 2, you'll need to reach the beginning of the endgame. You'll need to:

• Reach level 30
• Complete the District Union Arena, Roosevelt Island, and Capitol Building Strongholds

Once those are complete, you'll receive a call to head back to the White House. Head to the table on your immediate left, by the vendor that lets you allocate skill points and SHD Tech points, and you'll be able to pick up your first Specialization weapon. Don't forget that you can switch to the other Specializations at any time, just head back to that particular vendor.

Source