My subdomain was keep deleted automatic

My subdomain was keep deleted automatic, How to find and stop the API delete my CNAME ?

You’d have to change your API key.

Thanks. It’s not work fine. But my previous setup on my wordpress Cloudflare plugins. It show a Forbidden error.

Should I simultaneously install the plugins and integrate to my wordpress or I can just delete that plugins ?

If you reset your key, you will have to copy that key to plugins you trust.