very similar to the issue mentioned in the below link , i am facing the same problem.
I am using ZeroSSL and have created the public_html/.well-known/acme-challenge , placed the keys in the folder and checked the permissions as well.
As informed by JuergenAuer, i have created a test 12345 file in acme-challenge, and accessed via
http://talkpool.com/.well-known/acme-challenge/12345 and i get the same error
My domain is: talkpool.com
It produced this output: 404 not found error ; oops the page cannot be found
My web server is (include version): apache 2.4.39
The operating system my web server runs on is (include version): linux
My hosting provider, if applicable, is: Godaddy
I can login to a root shell on my machine (yes or no, or I don't know): No
I'm using a control panel to manage my site (no, or provide the name and version of the control panel): Yes
Any help to get this sorted is much appreciated