1. Select the HTTP validation method. The screenshot will show you how to complete the validation.

Create a Validation File
Create a file named 007BDDFAC9157321D1071420BE72FEA8.txt in the /.well-known/pki-validation/ directory.

File Content:

205acf83f2718baa25ead1cd95bb2891b8e2c4818586a5bea3046f16b37b080f comodoca.com  

Verify via URL
Access the following URL to complete validation (note that validation may take time to process):

http://example.com/.well-known/pki-validation/007BDDFAC9157321D1071420BE72FEA8.txt  

Replace example.com with your actual domain name.

Step-by-Step Commands

# Create the required directory structure  

root@C20210915137000:/var/www/html# mkdir -p .well-known/pki-validation/  

# Navigate to the directory  

root@C20210915137000:/var/www/html# cd .well-known/pki-validation  

# Create and edit the validation file  

root@C20210915137000:/var/www/html/.well-known/pki-validation# vi 007BDDFAC9157321D1071420BE72FEA8.txt  

After saving the file, ensure it is accessible via the validation URL. Allow some time for the validation to complete.

root@C20210915137000:/var/www/html/.well-known/pki-validation# /etc/init.d/apache2 restart

2. Test after adding DNS. After configuring on the machine, test the webpage.

http://example.com/.well-known/pki-validation/007BDDFAC9157321D1071420BE72FEA8.txt

The page opens normally; just wait for it to take effect.
After the final verification is completed, refresh the order page to see the verification status as completed. Then download the certificate (CERT) to your local machine.

Customers can choose according to the web service they have set up.
Apache and Nginx are web servers designed for Linux.
IIS is a web server for Windows.
Tomcat is a web server for Java-based applications.