Migrate Ruby on Rails Site to current version and host on Heroku

Please review attached Heroku download. I would like to have the source updated and site hosted on Heroku. The site has database links to Amazon S3 which is still as it was the last time the site was live.
I believe that the attached source is in Ruby 2.4.1 and Rails 5.2.1.1.
I would like both Ruby and Rails version to be made current.