When you schedule a meeting with FreeBusy, the email that you’re signed in with becomes the default meeting organizer. You can change it.

Step 1: Go to Appointment Booking and Click on "Edit Appointment Types"

Step 2: Go to the appointment type where you wish to change the calendar.

Step 3: Click on "change host"

Step 4: Add email associated with calendar where you wish to receive the given meeting and remove the old email.

Step 5: Click on save.

Moving forward all meetings you receive will go to this calendar.

If you are scheduling meeting using Plugin such as Chrome Extension or Outlook Add-in you have to ensure you are signed-in into respective application with email where you wish to receive meeting.