Follow the steps in this connection process to connect your calendar service to the software provider. This connection process is hosted by Cronofy and it allows us to gain access to your calendar service and broker that access out to your software provider.
Step 1: Configure a Service Account
First create a Service Account with ApplicationImpersonation role on one or more mailboxes. Details on how to do this can be found here: https://msdn.microsoft.com/en-us/library/office/dn722377(v=exchg.150).aspx
This role can be assigned to allow access to a subset of users and or the entire organization as desired.
You can test the configuration using the Microsoft Remote Connectivity Analyzer. More details can be found about testing in our help article Testing Enterprise Connect configuration for Office 365 and Exchange
Step 2: Authorizing Access
For this step you will need the Service Account credentials and an email address of a user or resource mailbox configured for impersonation. If you don't have Autodiscovery configured for your domain then you will also need the public Exchange Server URL.
Your software provider will provide you with a button or link to follow to connect your calendars with their service.
After selecting Office365 or Exchange you will see a screen similar to this.
This will verify the Service Account credentials and use them to impersonate the user associated with the Impersonation email. Once complete you will be redirected back to your software vendor's application and they will be able to synchronize your user/resource calendars.