Within Breeze, select the "Events" tab from the top right.
Click the gear icon next to "Add Event" and choose "Google/Apple Integration" from the dropdown menu.
Click the "Breeze → External Calendar" button.
Copy the URL for the Breeze calendar you wish to include on your external calendar.
Go to your external calendar (Google Calendar, Apple Calendar, etc) and provide the URL in the appropriate field.
Navigate to your Google Calendar.
On the left, click the plus sign to "Add other calendars."
Select "From URL," paste your Breeze iCal calendar URL and click "Add Calendar."
Navigate to your Apple Calendar.
On the top toolbar, select "File > New Calendar Subscription..."
Provide your Breeze iCal calendar URL.
On your mobile iOS device, navigate to "Settings > Accounts & Passwords > Add Account."
Select "Other" from the bottom of the list.
Select "Add Subscribed Calendar."
Provide your Breeze iCal calendar URL.