Once connected to your Gandi v5 interface, click on the domain name of your website (here “kwanko.site”) then select the section “DNS records”:
Click on the “Add record” button in the top right corner.
Select “CNAME” in the drop down menu then, in the “Name” field, enter the subdomain generated by Kwanko.
In the “Hostname” field, enter “custom.metaffiliation.com.” (do not forget the ending dot).
Validate by clicking “Create”.