If you do not have cURL installed on your server, you will not be able to use the "Quick store update" or the automatic store update features.  You will need to download your store from The Factory and import it using this form.

1. In The Factory, go to the Store you want to import.
2. Hover over the "Store" tab at the top and scroll down to Download store > For plugin version 3.x.  This will download a file with a name like "store_xxxx.sql" to your computer's downloads folder.
   
3. Go back to Tools > Datafeedr and under "Manual store update", click "Browse" and find the file you just downloaded.
   
4. Click "Update".

The update process may take a few minutes depending on how large your store is.  Once the import is complete, you will see a "success" message.