WP Google Analytics API Key, Client Secret and Client ID ?

You don’t need those please check the documentation and the introductory video.

Everything is straight-forward.

Before authorizing the plugin, please make sure that Google Analytics -> General Settings -> use your own API Project credentials is not selected.

I don’t know where it is ?

Google Analytics -> General Settings -> use your own API Project credentials is not selected

So complicated !

Where is it on the screen ?

If you know, please tell me !

Let’s take things slowly, please follow the steps described on the documentation page and watch the video from there.

After you do, try to describe exactly what doesn’t work for you, giving as much details as possible.

Please note that you need to create a Google Analytics account first (you’ll find details about that at the begging of the documentation page).

I couldn’t authorise the plugin, the error report says that my activation code has been redeemed. But I have never used this plugin before.