If you use Google as your domain provider and want to set up custom tracking domain, please follow these steps:
Log in to your Instantly account in one tab, and your Google domains in the other
Go in My Domains and hit the Manage button
From the left-hand side menu, click on DNS
Click on Manage custom records
Click on Create new record
Go to Instantly account settings, check the Use custom tracking domain, and copy the data from there for a new record
Paste the data
Host name: inst
Record type: CNAME
TTL: 3600
Data: prox.itrackly.com
Click Save
In Instantly, in the account settings, under Your tracking domain or subdomain enter: inst.yourdomain.com (change it with your sending domain)
Click on Check Status
After both SSL and CNAME records have been verified, you can go ahead and save changes.