So the documentation to go something like this...
Step 1. Download the software package for your device
Step 2. On your Synology go to Control Panel and then under Applications click Web Services. Put a check in the box to Enable Web Station if it already has not been.
Step 3. Open Package Center and click on Settings, under Trust Level select Any Publisher.
Step 4. Install the PERL package under Utilities.
Step 5. Click Manual Install and point it to the file downloaded in Step 1.
Step 6. Open Package Center and click on Settings, under Trust Level select Synology Inc.
Step 7. If there are problems logging in the iDrive app on your Synology, clear the cache on your browser, ie Firefox or Safari.
Step 8. Enjoy having IDrive Cloud backup on your Synology NAS!