letter_opener tab displaying nothing

Question

I am new to rails and I have an application that is supposed to send a confirmation email after creating a booking however, when I go to the /letter_opener tab after creating a booking nothing shows up

application_mailer.rb

class ApplicationMailer < ActionMailer::Base
default from: "support@flightbooker.com"
layout "mailer"
end

passenger_mailer.rb

class PassengerMailer < ApplicationMailer

 def booking_confirmation
    @passenger = params[:passenger]
    @booking = params[:booking]
    @flight = params[:flight]

    mail(to: @passenger.email, subject: "Confirmation Email")
end

end

bookings_controller.rb

 class BookingsController < ApplicationController

 include BookingsHelper

 def new
    @booking = Booking.new
    @selected_flight = Flight.find(params[:flight])
    @passengers_count = params[:passengers].to_i
    @passengers_count.times{@booking.passengers.build}
 end

 def create

    @booking = Booking.new(booking_params)

    if @booking.save

        
    @booking.passengers.each do |pax|
        PassengerMailer.with(passenger: pax).booking_confirmation.deliver_now
      end
      
        flash[:success] = 'Booking saved!'
        redirect_to booking_path(@booking)
    else
        flash[:alert] = "An error has occured!"
        render "new"
    end
 end

 def show

    @booking = Booking.find(params[:id])
 end





end

Gemfile

 source "https://rubygems.org"
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }

 ruby "3.1.2"

 # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
 gem "rails", "~> 7.0.4"

 # The original asset pipeline for Rails [https://github.com/rails/sprockets-rails]
 gem "sprockets-rails"

 # Use sqlite3 as the database for Active Record
 gem "sqlite3", "~> 1.4"

 # Use the Puma web server [https://github.com/puma/puma]
 gem "puma", "~> 5.0"

 # Use JavaScript with ESM import maps [https://github.com/rails/importmap-rails]
 gem "importmap-rails"

# Hotwire's SPA-like page accelerator [https://turbo.hotwired.dev]
gem "turbo-rails"

# Hotwire's modest JavaScript framework [https://stimulus.hotwired.dev]
gem "stimulus-rails"

# Build JSON APIs with ease [https://github.com/rails/jbuilder]
gem "jbuilder"

# Use Redis adapter to run Action Cable in production
# gem "redis", "~> 4.0"

# Use Kredis to get higher-level data types in Redis 
[https://github.com/rails/kredis]
# gem "kredis"

# Use Active Model has_secure_password 
[https://guides.rubyonrails.org/active_model_basics.html#securepassword]
# gem "bcrypt", "~> 3.1.7"

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem "tzinfo-data", platforms: %i[ mingw mswin x64_mingw jruby ]

# Reduces boot times through caching; required in config/boot.rb
gem "bootsnap", require: false

# Use Sass to process CSS
# gem "sassc-rails"

# Use Active Storage variants 
[https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
# gem "image_processing", "~> 1.2"

group :development, :test do

See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-

the-debug-gem
gem "debug", platforms: %i[ mri mingw x64_mingw ]
end

group :development do
  # Use console on exceptions pages [https://github.com/rails/web-console]
 gem "web-console"

  # Add speed badges [https://github.com/MiniProfiler/rack-mini-profiler]
  # gem "rack-mini-profiler"

  # Speed up commands on slow machines / big apps [https://github.com/rails/spring]
  # gem "spring"

  gem 'letter_opener_web'

end

group :test do
  # Use system testing [https://guides.rubyonrails.org/testing.html#system-testing]
  gem "capybara"
  gem "selenium-webdriver"
  gem "webdrivers"

end

development.rb

require "active_support/core_ext/integer/time"

Rails.application.configure do
  # Settings specified here will take precedence over those in config/application.rb.


  # In the development environment your application's code is reloaded any time
  # it changes. This slows down response time but is perfect for development
  # since you don't have to restart the web server when you make code changes.
  config.cache_classes = false

  # Do not eager load code on boot.
  config.eager_load = false

  # Show full error reports.
  config.consider_all_requests_local = true

  # Enable server timing
  config.server_timing = true

  # Enable/disable caching. By default caching is disabled.
  # Run rails dev:cache to toggle caching.
     if Rails.root.join("tmp/caching-dev.txt").exist?
    config.action_controller.perform_caching = true
    config.action_controller.enable_fragment_cache_logging = true

    config.cache_store = :memory_store
    config.public_file_server.headers = {
      "Cache-Control" => "public, max-age=#{2.days.to_i}"
     }
  else
    config.action_controller.perform_caching = false

    config.cache_store = :null_store
  end

  # Store uploaded files on the local file system (see config/storage.yml for 
options).
  config.active_storage.service = :local

  # Don't care if the mailer can't send.
  config.action_mailer.raise_delivery_errors = true

  config.action_mailer.delivery_method = :letter_opener
  config.action_mailer.perform_deliveries = true


  config.action_mailer.perform_caching = false

  # Print deprecation notices to the Rails logger.
  config.active_support.deprecation = :log

  # Raise exceptions for disallowed deprecations.
  config.active_support.disallowed_deprecation = :raise

  # Tell Active Support which deprecation messages to disallow.
  config.active_support.disallowed_deprecation_warnings = []

  # Raise an error on page load if there are pending migrations.
  config.active_record.migration_error = :page_load

  # Highlight code that triggered database queries in logs.
   config.active_record.verbose_query_logs = true

 # Suppress logger output for asset requests.
  config.assets.quiet = true

  # Raises error for missing translations.
  # config.i18n.raise_on_missing_translations = true

  # Annotate rendered view with file names.
  # config.action_view.annotate_rendered_view_with_filenames = true

  # Uncomment if you wish to allow Action Cable access from any origin.
  # config.action_cable.disable_request_forgery_protection = true



end

routes.rb

Rails.application.routes.draw do
  # Define your application routes per the DSL in 
https://guides.rubyonrails.org/routing.html

  # Defines the root path route ("/")
  root "flights#index"

  resources :flights
  resources :airports 
  resources :bookings

  mount LetterOpenerWeb::Engine, at: "/letter_opener" if Rails.env.development?
end

if you still need more code here is a link to my github https://github.com/Michael-Mehta/odin-flight-booker