I want to get data about discussions on a GitHub organisation e.g. all discussions with author, text, catagory etc.

I am using GitHub Apps in order to integrate GitHub in our product.
Looks like I need to have the app installed (not only request a token) in order to list user’s private repos.
So what I am doing is opening a pop up with the installation of the app, using this link https://github.com/apps/APP-NAME/installations/new
This works fine for the first time, the app gets installed and I receive the code to exchange for the token.
The problem is when the user already has the app installed, I would expect this new installation dialog to skip the installation setup(since the user already did that) and instead give me the access token and close the pop up.
Do I have any way to achieve that? Maybe specifying some kind of parameter?
If not, can I use git hub apps in some way that allows me to retrieve the private repos without having to install it (AFAIK the legacy Oath apps allow you to do that by specifying scopes)?

Does anyone know if it is possible on Github to search by words among many repositories?
For example, I want to obtain all the repositories of the “gophers” organization that have the word “charlie” in the name of the repository and that within the repo in any of the branches there is the word “namespace (Or at least in a specific branch)”. Is this possible on github?

Simple question

I’m writing some automation processes in c# (not really relevant) and I’ve been using the following URL format to fetch zip file from github: