You can configure your custom domain to point to a reverse proxy using Nginx/Apache web server. This approach is mainly for an IT audience. You should use Cloudflare to set up your custom domain if you have little or no technical knowledge.
The reverse proxy allows you to set up a tracking page with your domain on your web server using your SSL certificate. When a customer goes to your tracking page, the reverse proxy is called first. It acts as an intermediary between your domain and TrackMage so that it can use your SSL certificate.
Here is a simple illustration of how it works:

Here is how to configure a reverse proxy:
Step 1.
Go to your DNS provider and point your domain/subdomain to your web server using A record.
Step 2.
Then add the config according to the type of your web server. This step might require advanced server configuration skills. Please contact your IT department.Nginx
server { listen 80; listen 0.0.0.0:443 ssl; ssl_certificate fullchain.pem; ssl_certificate_key privkey.pem; server_name tracking.my-business.com;
location / { proxy_pass https://my-business.trackmage.com/; } }
Apache
<VirtualHost *:80> ServerAdmin support@example.com ServerName tracking.my-business.com Redirect permanent / https://tracking.my-business.com/ </VirtualHost><VirtualHost *:443> ServerName tracking.my-business.com SSLEngine on SSLCertificateFile cert.pem SSLCertificateKeyFile key.pem ProxyPreserveHost On ProxyPass / https://my-business.trackmage.com/ ProxyPassReverse / https://my-business.trackmage.com/ </VirtualHost>