3rd Party Apps

I have followed this tutorial from this site
https://support.wdc.com/knowledgebase/answer.aspx?ID=17873

The problem is when I load the dashboard and go to apps I dont get the option to add, as follows

Help needed please.

It does not apply to the single-bay WD My Cloud, as noted in the article (Bottom section).

Thanks for the reply. Time to get a Synology I think.