Sending an email using an template using the sendgrid-ruby library

example-template.rb

require 'sendgrid-ruby'
require 'dotenv'
Dotenv.load

sendgrid_apikey = ENV['SENDGRID_APIKEY']

client = SendGrid::Client.new do |c|
  c.api_key = sendgrid_apikey
end

recipient = SendGrid::Recipient.new('elmer.thomas@sendgrid.com')
recipient.add_substitution(':name', 'Elmer')
recipients = []
recipients << recipient
template = SendGrid::Template.new('13b8f94f-bcae-4ec6-b752-70d6cb59f932')

mail_defaults = {
  from: 'dx@sendgrid.com',
  html: '<h1>I like email</h1>',
  text: 'I like email',
  subject: 'Email is great',
}

mailer = SendGrid::TemplateMailer.new(client, template, recipients)
mailer.mail(mail_defaults)