For Outlook Desktop versions 2010 and 2013, follow this entire process to create a two-way calendar sync.
Click on on “Account Settings.”
Then click on “Account Settings” in the dropdown.
Click on the “Internet Calendars” tab.
Click on “New.”
Copy and paste the URL from SignOffPro below and click “Add.”
Next, uncheck the “Update Limit” box as shown below, then click “OK.”
Your Internet Calendar should show SignOffProScheduler. Click “Close.”
Go to Outlook Desktop and click on the calendar icon in the lower left-hand corner of the screen.
Locate the calendar you wish to sync and right click on your calendar name in the left-hand side, and select "publish to the internet and/or publish to WebDAV server."
Enter the URL below in the popup that will appear:
Selected "advanced" and ensure your settings match the below:
Finally click "ok".
When prompted enter the following:
The two-way sync of Outlook Desktop and SignOffPro is now complete for Outlook Desktop 2010 and 2013.