By default, when links are shared on Facebook, a preview that gets displayed on the newsfeed similar to the following :

As you will notice, the domain name that is shown by Facebook is "BLOG.HUBSPOT.COM.VIA.3NG.IO", however you can also rebrand this to display "Via" your own domain name.

PLEASE NOTE: The via domain or subdomain must match the url you are using for your custom share url (see here for further info).

Edit your DNS in Cloudflare or directly via your webhost

So, let's say that for example, the custom domain name that you're using for that campaign is "mydomain.com", you will only need to add the following record to your domain's DNS configuration:

Once you do that, when Facebook tries to create the preview of your "Share" link, the system will automatically look for the "*.via" version of your custom domain name and use it

Subdomain Configurations

If you are using a subdomain, then the setup is slightly different. you need to add the subdomain after the "via".

So, for example, if your campaign's custom domain name is a subdomain like "news.mydomain.com", the DNS record should be as following:

Once the DNS configuration propagates successfully, the subdomain will be working correctly.

PLEASE NOTE: You do not need to add a via subdomain into the custom domains section of your Wishloop account. This happens automatically for any domain you add.

Further Reading:

Using your own custom domain name or sudomain

How to use your own custom domain name with iQueue

Installations

Using your own custom domain name or subdomain

How to install Bumpleads on my website?

How to set the homepage/root of my subdomain/domain name?

The "SpeedLeads" Browser Extension

Installing the Bumpleads WordPress Plugin

How to rebrand "via" domain in Facebook links preview

How use the Shopify Widget?