letsencrypt wildcard ssl certificate on Amazon Linux + Apache

mkdir certbot

cd certbot

wget https://dl.eff.org/certbot-auto

chmod a+x certbot-auto

sudo ./certbot-auto certonly  --server https://acme-v02.api.letsencrypt.org/directory  --manual --preferred-challenges dns  -d *.domainname.com

For putting TXT record in NameCheap:

In HostName, put _acme-challenge, in value put the string given on the command line.

To check whether the txt record is deployed:
dig -t txt _acme-challenge.domainname.com

Then in httpd.conf:

<VirtualHost *:443>

    DocumentRoot "/var/www/html/somepath"

    ServerName other.domainname.com

    ServerAlias *. domainname .com

    SSLCertificateFile /etc/letsencrypt/live/ domainname .com-0001/cert.pem

    SSLCertificateKeyFile /etc/letsencrypt/live/ domainname .com-0001/privkey.pem

    SSLCertificateChainFile /etc/letsencrypt/live/ domainname .com-0001/fullchain.pem

    ErrorLog logs/ domainname -error_log

    CustomLog logs/ domainname -access_log common

    <Directory "/var/www/html/somepath">

        Options Indexes FollowSymLinks

        AllowOverride All

        Order allow,deny

        Allow from all

    </Directory>

</VirtualHost>