Does the Time Machine Backup Share have to be public?

I was trying to secure as many of the shares on my drive as possible and when I tried to make the TimeMachinesBackup Share not public my computer’s time machine backup cannot access it anymore.  Is this normal behavior?  How do I password protect it?

Nevermind I figured this out.  You just need to log in to the storage device as your username instead of guest when you select the disk in Time Machine and make the share private not public.