carrierwave-dropbox authorization - ruby-on-rails

Question

I have created an app on dropbox and I am following the https://github.com/robin850/carrierwave-dropbox steps but cannot get the access token.
It has 400 bad request although I am providing correct key and app secret but cannot get the link to allow my app.
Here is the error and I am creating a ruby-on-rails app:
rake aborted!
DropboxAuthError: Error getting request token. Is your app key and secret correctly set? Server returned 400: Bad Request.
/var/lib/gems/2.3.0/gems/dropbox-sdk-1.6.5/lib/dropbox_sdk.rb:277:in `get_token'
/var/lib/gems/2.3.0/gems/dropbox-sdk-1.6.5/lib/dropbox_sdk.rb:293:in `get_request_token'
/var/lib/gems/2.3.0/gems/dropbox-sdk-1.6.5/lib/dropbox_sdk.rb:299:in `get_authorize_url'
/var/lib/gems/2.3.0/gems/carrierwave-dropbox-1.2.1/lib/carrierwave/dropbox/rake.rb:13:in `authorize'
/var/lib/gems/2.3.0/gems/carrierwave-dropbox-1.2.1/lib/carrierwave/dropbox/authorize.rake:11:in `block (2 levels) in <top (required)>'
/var/lib/gems/2.3.0/gems/rake-12.1.0/exe/rake:27:in `<top (required)>'
Tasks: TOP => dropbox:authorize
(See full trace by running task with --trace)

Answer 1

Have you configured carrierwave
CarrierWave.configure do |config|
config.dropbox_app_key = ENV["APP_KEY"]
config.dropbox_app_secret = ENV["APP_SECRET"]
config.dropbox_access_token = ENV["ACCESS_TOKEN"]
config.dropbox_access_token_secret = ENV["ACCESS_TOKEN_SECRET"]
config.dropbox_user_id = ENV["USER_ID"]
config.dropbox_access_type = "dropbox"
end

Answer 2

Here is an example hope it can work:
1- create a file config/config.yml and provide here your keys:
default: &default
development:
<<: *default
app_key: "your_app_key"
production: &production
<<: *default
app_key: "your_app_key"
staging: &staging
<<: *default
app_key: "your_app_key"
2 - in environment.rb file
# Load the Rails application.
require_relative 'application'
APP_CONFIG = YAML.load_file("#{Rails.root}/config/config.yml")[Rails.env]
# Initialize the Rails application.
Rails.application.initialize!
3 - then you can use in in carrierwave.rb file
CarrierWave.configure do |config|
config.dropbox_app_key = APP_CONFIG['app_key']
//and your another configuration so on...
}
end
if you have right api keys permission then it should work. thanks