Outdated info on barrier creation

[vkotovv]

It is stated in the Barrier article:

Setting up barriers requires a few steps. First we create a vertical barrier by selecting Add Vertical Barrier from the context menu.

At this moment (AS 3.3.1, androidx.constraintlayout:constraintlayout:1.1.3), you have to click Helpers -> Add Vertical barrier in the context menu.
Gif example for doing this is also outdated.