If you have an Enterprise license to Big River, you will be able to publish your catalogs and landing pages via URLs based on your domain name, for example "transactions.yourorg.org".  Setting this up requires someone in your organization who has access to your web domain registry to make a change in what is called the DNS Zone File ("adding a CNAME record").  Steps for doing so where your domain is registered with GoDaddy.com are below.  If your domain is hosted by another provider, please open a support issue to get detailed support.

Log into GoDaddy and access your domains:

Click the "DNS" button next to the listing for your domain.  A  listing of DNS file entries will appear.  At the bottom of the list, select the Add button and enter your desired subdomain  name (e.g. "transactions" or "donations" - the specific name will be specified by you and communicated to Big River as part of initial setup), and the name of the server provided to you by  Big River.

Select Save to complete the new entry.  The new entry and the link to Big River may take up to a few hours to be available from any web browser.

Making this connection to your subdomain secure requires an additional step taken by Big River as part of your initial setup.  You will receive an email from GoDaddy requesting permission for your subdomain to be added to one of Big River's SSL certificates.  Once you grant permission by clicking a link in the email, your subdomain will be secure overnight.  

If you do not receive an email from GoDaddy, please open a support ticket to get detailed support.