Give a name, some description to the API, and agree the terms.
Go to the Smart Slider's back-end Global Settings → Flickr generator, and copy out the Callback url.
Open the Edit auth flow for this app link in a new window, because you will need the information from this page.
Paste the Callback URL into here, and click on SAVE CHANGES.
Go back to the Step 6 page (if you closed the page, click on View in the right side under Admin) and copy the Key and Secret.
Paste them to the Smart Slider's back-end Global Settings → Flickr generator. (Make sure, that you don't have any empty space characters in the end or beginning of them.)
Click on Request token, and authorize the linking to your account.
You will see the token appearing in your settings, and you should save on it.
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 Flickr 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.
Privacy - You can choose to show only the public photos, but you can also choose to show from differently private images.
Album - You can select one album from your albums.
Gallery - You can select one gallery from your galleries.
User name or ID - The username or the ID of the user from who you want to get the images. If you leave it on "me", it will return your images.
Tags - You can search for tags separated with comma.
Search in title, description or tags - Photos who's title, description or tags contain the text will be returned.
Privacy - Return photos only matching a certain privacy level. This only applies if you call your own photos.
Type - The returned content type:
photos, screenshots, and 'other' (all)
photos and screenshots
screenshots and 'other'
photos and 'other'
My photostream, My album, My photogallery
image - Either the original, or the large version of the image.
thumbnail - Either the medium, or the large version of the image.
title - The title of the image.
description - The description of the image.
url - URL to the photostream.
owner_username - The username of the image's owner.
author_name - Either the real name, or the username of the image's owner.
author_url - URL to the author.
url_t url_s ... url_o - Different sizes of the image.
owner - The owner of the image.
dateupload - The upload date of the image.
datetaken - The date, when the image was taken.
ownername - The name of the image's owner.
views - The number of views of the image.
tags - The tags of the image.
latitude - The latitude of the image.
longitude - The longitude of the image.
image - The large size image.
thumbnail - The small size image.
title - The title of the image.
url - Url to the image.
url_b ... url_z/1 - Different sizes of the image. These are based on the uploaded images' sizes, if they were made or not, for example url_h is the biggest, but if you uploaded a small image, flickr won't create that.