Issues with chatbot API Authentication

Thank you very much, that answered my question.

I still really don’t understand the need of web page to authenticate. I understand when you have an application which has other users, for example Nightbot, Betterttv etc., but it seems strange to have to create a web page just to authenticate my own account.
I’ve never meet with something like that. But that doesn’t matter, I just thought that I’m doing something wrong before.

The last thing I still don’t understand in this concept is this:

So in my case, I aim to fully automatize the authentication flow - but even though I will have to click a button to allow access? Sorry if I misunderstood you again.