Bootstrap issue with Ruby on Rails 6 - ruby-on-rails

Question

I am trying to implement bootstrap to my app and having issues when I try to implement some modals from bootstrap.
Created my app with using following command;
rails new HR-app -J -C --database=postgresql
My gem file
source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }
ruby '2.5.5'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 6.0.2', '>= 6.0.2.2'
# Use postgresql as the database for Active Record
gem 'pg', '>= 0.18', '< 2.0'
# Use Puma as the app server
gem 'puma', '~> 4.1'
# Use SCSS for stylesheets
gem 'sass-rails', '>= 6'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.7'
# Use Active Model has_secure_password
# gem 'bcrypt', '~> 3.1.7'
# Use Active Storage variant
# gem 'image_processing', '~> 1.2'
# Reduces boot times through caching; required in config/boot.rb
gem 'bootsnap', '>= 1.4.2', require: false
group :development, :test do
# Call 'byebug' anywhere in the code to stop execution and get a debugger console
gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
gem 'rspec-rails', '~> 4.0'
end
group :development do
# Access an interactive console on exception pages or by calling 'console' anywhere in the code.
gem 'web-console', '>= 3.3.0'
gem 'listen', '>= 3.0.5', '< 3.2'
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
gem 'spring-watcher-listen', '~> 2.0.0'
gem 'rspec-rails', '~> 4.0'
gem 'webpacker', '~> 5.1', '>= 5.1.1'
end
# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
environment.js file
const { environment } = require('#rails/webpacker')
const webpack = require('webpack')
environment.plugins.append('Provide',
new webpack.ProvidePlugin({
$: 'jquery',
jQuery: 'jquery',
Popper: ['popper.js', 'default']
})
)
module.exports = environment
application.scss file
#import "bootstrap/scss/bootstrap";
application.js file
import 'bootstrap'
console.log('Hello World from Webpacker')
example I took from bootstrap and index file of my scaffold;
<!-- Button trigger modal -->
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal">
Launch demo modal
</button>
<!-- Modal -->
<div class="modal fade" id="exampleModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
<div class="modal-body">
...
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
<button type="button" class="btn btn-primary">Save changes</button>
</div>
</div>
</div>
</div>
And this is how it looks;
It is not desired look of modal and also it is no functional (no error). You can see the live demo of the modal here. getbootstrap.com/docs/4.0/components/modal –
How can I implement the modal as live demo from bootstrap.
Any help will be appreciated!
Thanks :)