Installing Apps is very simple with UNA. But before you can do that, we need to fix #2 first.. So here is how you do that:

First, you need to make sure that you entered the Key and Secret from UNA into your site's Studio > Settings > General area. If needed, you can reset the key by doing the steps below. 

First, go to this URL here at UNA and click the button on the far right to "reset" your key:

https://una.io/page/my-sites

Then re-add the key (Add New Key):

You will need to put the FULL URL to your website there. So for example: 

http://www.eronett.no 

Once that is done, go back into enter the Key/Secret in your site's Studio > Settings > General area.

You check to make sure it is working by going into Studio > Apps Market and click something like Storefront.

Depending on the plan you have here at UNA, you can see what already comes with UNA by clicking the Purchased link on the side menu of the Apps Market. You can simply click the Install button on anything you may want to install. 

For any "Free" apps in the Apps Market, all you need to do is click the Download button first. Then click the "Downloaded" link on the side menu to see if it downloaded. From there, you can click install. 

All done! No need to FTP/Extract,etc.