Thanks your awesome video. I had ever use the gem 'devise' and include the confirmable module, when i deploy my app on heroku, i use the sendgrid add-on to send email confirmation according to the heroku guides, i want to use the ssl function so i use the code in "config/enviroments/production.rb" as follow ```ruby config.force_ssl = true config.action_mailer.raise_delivery_errors = true config.action_mailer.delivery_method = :smtp host = "note-book-diary.heroku.com" config.action_mailer.default_url_options = { protocol: "https", host: host } ActionMailer::Base.smtp_settings = { address: "smtp.sendgrid.net", port: 587, authentication: "plain", user_name: "xx", password: "xx", domain: "heroku.com", enable_starttls_auto: true } ``` when i reach the link https://note-book-diary.heroku.com/, the response return ok, but when i click the email confirmation , i get the wrong response "NET::ERR_CERT_COMMON_NAME_INVALID" The chrome error messages show the the website use HSTS and can't reach it. can you do me a favor to find the solution? Thanks a lot!