How to setup UE source so it gets detected by Unreal Launcher?

As I recently lost my windows partition I’m doing whole setup from scratch so I would LOVE to know how to properly setup Git locally to use with UE source and Unreal Launcher the same way.
My main issue is where to put source code (to which directory on HDD) so it gets properly detected by Unreal Launcher. What steps do I need to undertake to have this working?
I plan to use content from marketplace but without launcher detecting engine marketplace is rendered useless for me :expressionless:
How do I know Unreal Launcher detected my GitHub version of engine and is able to add content to it?

Anyone that can provide pointers is welcome!
Meanwhile I wait for all my programs to download and install.
Thank you.