Add package by name window type

Unity Engine
,
1

Does anybody know of what type the window is that appears when you click on the plus icon → Add package by name…?

Here a screenshot of it (it is marked blue):

8463380--1123889--upload_2022-9-24_23-53-54.png
8463380--1123889--upload_2022-9-24_23-53-54.png669×825 67.8 KB

I am unable to find any type that matches it.

2

Please disregard, the type is DropDownContainer.