Application error with error code H10 of a ruby on rails app deployed on Heroku

I encountered an application error after having deployed my Ruby on Rails app to Heroku. The app is developed on Cloud9 from AWS and is called "wcslux_app". The app is equivalent to the hello_app from Hartl's rails_tutorial. In the Log file, I can see there is an error code H10 on GET with path "/" and ""/favicon.ico".

After having followed the tutorial my app is not working in production on Heroku. I executed following commands to deploy the wcslux_app:

source \<(curl -sL <https://cdn.learnenough.com/resize>) 
rake log:clear 
rake tmp:clear 
source \<(curl -sL <https://cdn.learnenough.com/heroku_install>) 
heroku login --interactive 
heroku create 
git push heroku main

When visiting https://sheltered-beach-35205-f93f5210b58a.herokuapp.com, I was expecting to have the same results as obtained in my development environment IDE Cloud of cloud9 of AWS.

Gem file:

group :development, :test do
   gem "sqlite3", "1.4.2"
   gem "debug", "1.5.0", platforms: %i[ mri mingw x64_mingw ] 
end 

group :production do 
  gem "pg", "1.3.5" 
end

Solution

The setup of specific adapters for each environment in the database.yml config file is the solution . I have defined a sqlite adapter for development and test environments and a Postgres adapter for production environment.

default: &default
  adapter: sqlite3
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  timeout: 5000

development:
  <<: *default
  database: db/development.sqlite3

test:
  <<: *default
  database: db/test.sqlite3

production:
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  database: wcslux_app_production
  username: wcslux_app
  password: <%= ENV['WCSLUX_APP_DATABASE_PASSWORD'] %>