In The Division 2 you can unlock crafting to make your own items and weapons from blueprints. To unlock the crafting workbench we must recruit a staff member called Inaya.

Here's how to unlock crafting:

Recruit Inaya al-Khaliq from the Theater Settlement. She can be recruited after the first Main Mission "Grand Washington Hotel". Talk to her on the rooftop of the Theater Settlement.

Return to the Base of Operations (White House) where Inaya will wait on the ground floor for you. Talk to her once more to unlock the Crafting Station.

That's all there is to unlocking the crafting station in The Division 2. You will still need materials and blueprints to make items. The materials are found by looting objects in the game world or by dismantling items from the inventory. Blueprints are mainly awarded from side missions and bought from vendors. Always check the vendors and fast travel between settlements to see what they have for sale. To craft higher level items you must first upgrade the Workbench with the Bench Upgrade Blueprint - which you get automatically from story progression. Then simply interact with the workbench and hold Square (PS4) / X1 (Xbox One) to upgrade it (requires various materials).