Hello Betty,
This morning it seemed to be working fine (after we set it up on our end) - please recheck, maybe you do not need to do anything.
If you do, you can find the instructions via Settings / Site Settings / Additional domains. Basically, you need to setup your domain to point to CNAME sites.wildapricot.org
Let us know if you need any help.
Dmitry Buterin, Chief Apricot