How do you set up a custom domain using Wild Apricot? This is a common question from many Nicasio Design Wild Apricot customers. First, let me define what a custom domain means; “A domain name is the address that you type into a web browser address bar to get a website. An example of a domain name is www.website.com. A domain name is unique to a website and cannot be shared between different websites, and a custom domain name is one that is specifically for your website.”   Src: Website.Com

As a Wild Apricot account paid holder you can use this feature found in the admin: Go to Admin > Website > Settings > Domain Name > Add custom domain > within the admin section of your Wild Apricot account. Here you can enter your custom domain and please be sure to check the [Install free SSL certificate from Let’s Encrypt. Installation may take up to 30 minutes to complete. Verify by loading your site using https.] option.

Next, you will need to add the following DNS zones to your domain registrar or DNS manager:

1) CNAME
Name: www
Value: sites.wildapricot.org
 
2) CNAME
Name: default._domainkey.yourdomain.org
Value: dkim.wildapricot.org
 
3) A record
Name: yourdomain.org
Value: 34.226.77.200
 
4) TXT record
Name: yourdomain.org
Value: v=spf1 mx include:wildapricot.org ~all

Note it may take up to 48 hours for DNS to fully propagate. DNS propagation is the time to update DNS onto the server. Returning back to your Wild Apricot account admin and check the settings, and don’t forget to set your primary domain as www or non-www.

Finally, go to the admin and Traffic encryption (HTTP/SSL) section to set desired HTTP/HTTPS browsing options. This is not as difficult as it seems and after a few setting adjustments you should be all set.

Here is the full article from Wild Apricot Support Library:
Custom Domain Setup