```ruby
require 'bundler/setup'

require 'sinatra/base'
require 'active_record'

require_relative 'routes/quotes'

module Quotes
  class App < Sinatra::Base
    configure do
      set :db_adapter, 'sqlite3'
      set :db_database, 'quotes.db'
    end

    ActiveRecord::Base.establish_connection(
      adapter: settings.db_adapter,
      database: settings.db_database
    )

    use Routes::Quotes
  end
end
```

Connect to database using `Database.connect`
user
```ruby
require 'bundler/setup'

require 'sinatra/base'
require 'active_record'

require_relative 'db/database.rb'
require_relative 'routes/quotes'

module Quotes
  class App < Sinatra::Base
    configure do
      set :db_adapter, 'sqlite3'
      set :db_database, 'quotes.db'
    end

    Database.connect(adapter: settings.db_adapter, database: settings.db_database)

    use Routes::Quotes
  end
end
```
assistant