Bash:
#Using --register-unsafely-without-email
certbot certonly --standalone --register-unsafely-without-email -d example.com
#With Webroot Plugin
certbot certonly --webroot --register-unsafely-without-email -w /var/www/html -d example.com
#DNS Challenge (for wildcard certificates)
certbot certonly --manual --preferred-challenges dns --register-unsafely-without-email -d example.com -d *.example.com