There are different ways to do it. In this case "signet", the plugin of Dashub to be plugged in to your web browser, isn't installed. Firstcopy the url (the address) of the page you wish to save.
Go back to your Dashub
There are different ways to add an item. Inside your Dashub, click on the "Private deck" tab. Click on the plus sign to add your link into the corresponding folder.
Or you can click on the folder title. Inside the folder, click on the plus sign (top right).
When you click on the plus signe. A box will appear.
Paste the url (the address) of the web page
Check if the folder is ok on the left of Tag & Save. If it is ok, click on Tag & Save.
The box is divided into 2 parts. The first part is dedicated to the preview.. The second is where you can:
"Subscribe to the source" isn't implemented yet for SoundCloud.
Click on Save when you are done.