Where can i download the C++ API documentation locally ?

Hello, I am using Unreal Engine in order to help me to make my game, but since it’s almost impossible to remember 100% of the unreal engine API, i tend to often need the API reference, unfortunately it looks like the api reference is only available online here Unreal Engine API Reference | Unreal Engine Documentation
Do you know if there would be some way to download the full API reference locally as PDF or something like this in the case i don’t have internet one day ? To still be able to work on my project without issues
or is it maybe already integrated with the binary ? in this case where would it be in the Unreal Engine installation files ?
I’m using Unreal Engine 4.20 on Linux built from source

@SeleDreams, you already have it if you are using a built version from source code. In windows I am using visual studio and visual assist to access all quickly, even with the binary version you can access every class
The documentation is very basic, it is just a parser for the headers included in the unreal’s source.

where is this documentation ? (the directory where it’s included)