Teach Me how to Update my Ruby on Rails Gem File for Heroku

Hello, I am looking for a Ruby on Rails expert with experience deploying a rails app to Heroku. I have an application that requires several updates in the Gem file but I don't know how to do it. I'm a PHP developer and have no experience with Ruby on Rails. Here are the warnings I want to solve: ###### WARNING: There is a more recent Ruby version available for you to use: 2.4.10 The latest version will include security and bug fixes. We always recommend running the latest version of your minor release. Please upgrade your Ruby version. For all available Ruby versions see: [login to view URL] ###### WARNING: EOL Ruby Version You are using a Ruby version that has reached its End of Life (EOL) We strongly suggest you upgrade to Ruby 2.6.x or later ##### This app is using the Heroku-18 stack, which is supported until April 30th, 2023. A newer stack is available: Heroku-20. To upgrade, see: [login to view URL] ###### Unfortunately I cannot give the developer access to our source code, so I am looking for someone to do a zoom call with me to walk me through step by step what I have to do to fix this. Like I said I am a good php developer so I think I'll be easy to teach. Please place your bid based on an hourly rate, and you will bill me for every minute of our calls together. To ensure a smooth project I will only accept developers will excellent communication skills who are fluent in english.