If you want to share your busy times back into Outlook or Google Calendars so that your colleagues and friends can see the times when you are free/busy internally, here is how to go about it:

You would be able to get your URL so that you can automatically share calendar feed

Step 2: Subscribe the calendar

If you are sharing with your colleague, ask them to locate the option to subscribe the calendar. It gets automatically imported and your colleagues are made aware of times you are free or busy. This way you can share your Free or Busy times with your colleagues outside your organization. You can also send this link to you clients/customers.

For example in Outlook you can use option "Add Calendar" which allows you to subscribe the calendar.

Once you or your colleague have successfully subscribed the calendar feed you will be able to see Free/Busy events on the calendar similar to following screenshot.

That's it! This way you can publish you Free/Busy calendar.

Kindly note that this is available for Professional plans. See: Pricing | FreeBusy