When it is created, you will be redirected to its page (sometimes it has a bug and doesn't redirect automatically, so you could also refresh your page, and select the project from your list, if it seem to take too long, because it's probably already done), and you should go to the APIs & auth → APIs.
Look for the YouTube Data API, and click on Enable API.
Go to the Credentials, and click on Add credentials → OAuth 2.0 client ID.
Click on Configure consent screen.
Give a Product name and save on it.
Then go to the Smart Slider's back-end, Global Settings → YouTube generator, and copy the Callback url.
Copy the client ID and secret.
Go to the Smart Slider's back-end, Global Settings → YouTube generator, paste them there, and click on Request token. (Make sure that you don't have any empty space characters in the end or beginning of them.)
Allow your API to get access to your YouTube account.
You will receive a Token, and you should save the settings.
Now the api is done, and you can create a new slider, or use an existing one.
Choose to give dynamic slides to your slider.
Pick one of the YouTube generators.
Set up your generator, choose the settings you think you want, change the number of slides to how many do you want to be in your slider, change the cache expiration to the time you want your slider to look for new data, and if you want to, you can check, what will be on your slides in the record viewer.
Now you can start working on how your slides will look with the datas of the first slide. You can put down layers, and use the VARIABLE signs to put that data inside them, what you want there to be. If something is not clear, check out how the dynamic slide generators work.
Search term - The word you would like to search for in the videos.
Playlist - Choose one from your playlists from where you want to show the videos.
By search, By playlist
video_id - The id of the video.
video_url - The url of the video.
title - The title of the video.
description - The description of the video.
thumbnail - The default size thumbnail image of the video.
thumbnail_medium - The medium size thumbnail image of the video.
thumbnail_high - The high size thumbnail image of the video.
channel_title - The title of the the video's channel.