Lambertseter senter

From the main entrance, walk towards the H&M store until you see some stairs to the floor below on your right. The door is visible as soon as you've gone down. There is also a place there for breast feeding, so people with breasts and children can feed their children outside of the home without people shaming them.

It's not a gender neutral bathroom, but it has both the "male sign" and the "female sign" on the door, so as long as you feel comfortable using it, you should be perfectly safe there. There is only one room and toilet there and no stalls so you may have to wait in line to get in, though when I found it, nobody was there.

PS: There is a library in the same building where I found three books about transgender people displayed at the entrance, which I would recommend reading, especially if you are a child or youth. Stay safe my beautiful friends, and have an amazing day! :)