I don't see anything in your post that I can help with. That sounds like a question you should ask of the Cloudflare community. I found the below thread that might be a good starting place.
If you get a specific error about getting a Let's Encrypt cert let us know and we will try to help. If you do that please also complete the form questions you were shown as best you can. The more info we have the better and quicker we can advise.
Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
My domain is:
I ran this command:
It produced this output:
My web server is (include version):
The operating system my web server runs on is (include version):
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don't know):
I'm using a control panel to manage my site (no, or provide the name and version of the control panel):
The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot):