After this your application will appear in your list, and you should click on See application details under it's name.
Copy out the Consumer Key and the Consumer Secret.
Go back to our backend Settings → 500px generator, and paste the Key and Secret there, then click on Request token. (Make sure that you don't have any empty space characters in the end or beginning of the Key and Secret.)
Authorize the api to use your account.
You will see the token appearing in your backend, and you should save on 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.
Choose 500px - Collection.
Set up your generator, pick a collection, 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.