From this guide page for Watch Dogs Legion you will learn all the hidden Tech Point locations in Tower Hamlets.
Helmsmans Tracks [1]
In this restricted area, you will have to destroy a plywood wall (marked with a red X). There is another, identical wall behind it. You will find the Tech Point when you break the second wall as well.
Albion Bethnal Green Station [2]
You will find an unfinished staircase in the building. Climb the stairs, and you will find a room where the Tech Point is located.
Cemetery Park [3]
A small building is located in the corner of the park, and you will find the Tech Point there. You need to use the Spiderbot to get inside.
Wapping Albion Station [4]
The tech point is hidden on the roof of the building. You have to use a drone to get to it.
Thames Landing [5]
The Tech Point is in the room under the landing. You can't get in there from either side. Instead, you have to use the Spiderbot which is located inside.
Royal London Hospital [6]
Part of the hospital reaches over the street. There, you will find a small roof which holds a small scaffolding. The Tech Point is inside.
Albion Drones Factory [7]
The Tech Point is inside the building. Approach the door shown in the picture below. It is protected by an alarm which you must deactivate (unless you are wearing an Albion costume). Your objective is right next to the door. There is also a guard there - you can distract him or knock him down.
Whitechapel Terminus [8]
The Tech Point is located on the lower level of the complex. The safest way is to jump down to the area located right at the border with the restricted zone and throw the Spiderbot over the fence.
Brick Lane [9]
The tech point is on the roof of the building. All you have to do is fly a drone over there.
Old Spitalfields Market [10]
At the entrance, there is a building which can be accessed through the stairs. The Tech Point is inside. This area is guarded, so you will have to defeat at least one enemy.
Tower Of London [11]
There is a small cage in the courtyard. The Tech Point is inside. The area is guarded, so the safest thing to do is fly up there using a drone and drop the Spiderbot there.
Tower Bridge [12]
The Tech Point is at the very top of the bridge. To get there, you need to use the window located on one of the towers.
Then, go up the stairs to the very top. Once you get there, go outside above the street. This is the penultimate level of the bridge. The easiest way to collect the Tech Point is to by throwing the Spiderbot to the upper floor and using the robot to get it.