Let's Encrypt Wild Card Certificate Generation in IIS

Linux CentOS 7

cd /usr/local/bin
yum install letsencrypt OR wget https://dl.eff.org/certbot-auto OR sudo snap install --classic certbot
chmod 777 ./certbot-auto
cd certbot-auto
./certbot-auto certonly --manual --preferred-challenges=dns --email [email protected] --server https://acme-v02.api.letsencrypt.org/directory --agree-tos -d *.domain.com,domain.com
The above command would ask to add one TXT record to your DNS Records add it and then check using DNS Lookup Checker. If the record is updated and it shows then you can proceed further and press Enter on the terminal.
Remember the path where certificate files are generated. There would be 5 files as following:

Now to get those certificate installed in IIS, you need to download OpenSSL GnuWin32 on Windows system and copy all those certificate files to Windows New Folder on Desktop.
OpenSSL for Windows - Complete package, except sources
Install the program and copy those generated .pem files to Installed Path/bin
Open CMD with Administrator Rights then cd to that openssl bin path.
Execute the following command which would generate a .pfx file from .pem
openssl pkcs12 -export -out certificate.pfx -inkey privkey.pem -in fullchain.pem -certfile cert.pem
This would ask a password remember it and write down in the .txt file somewhere.
It would generate a certificate.pfx on that same location.
Now Open Start > Run > certlm.msc or Control Panel > Search certificate > Open Manage Computer certificates
Go to Web Hosting > Right Click empty space > All Tasks > Import > Select the certificate.pfx and add password and Import it.
Right Click imported certificate and View > Add Friendly Name.
Check Certificate in IIS.