How to push WAN IP( DDNS ), use pfSense to Cloudflare(A record), and how I fix the problem | Solved

The Answer is:
If you use a custom API key, you must use Zone ID for pfSense>DDNS>Username

and the story begins......
https://www.davidsideproject.com/how-to-push-wan-ip-ddns-use-pfsense-to-cloudflare/

pfSense document hasn't any remark......
Netgate