API endpoint link is working in Postman but not in Ruby on Rails with ActiveResource

I am working on Ruby on Rails application which requires to access an External API via GET requests. The request needs to send some parameters with request. I have used Activeresource gem for accessing API. The API request is working fine in Postman and giving expected records but gives me a 400 error from Rails application.

Following is the code

class PayRunEmploymentHeroBase < ActiveResource::Base
  self.site = "https://api.yourpayroll.com.au"
  self.user = ENV['EMPLOYMENT_HERO_USERNAME']
  self.element_name = ""
  self.include_format_in_path = false
  self.prefix = "/api/v2/business/:business_id/payrun?$filter=DateFinalised gt datetime':finalised_date'"
end

I am pasting here the details of 400 error while accessing the link from Rails app.

Reloading...
 => true
2.3.0 :006 > PayRunEmploymentHeroBase.find(:all, params: {:business_id => business_id, :finalised_date =>  finalised_date})
##############################################INFO##############################################
{
  "method": "get",
  "request_uri": "https://api.yourpayroll.com.au:443/api/v2/business/48058/payrun?$filter=DateFinalised gt datetime'2017-11-16'",
  "http_status": "400",
  "http_message": "Bad Request"
}
##############################################INFO##############################################
ActiveResource::BadRequest: Failed.  Response code = 400.  Response message = Bad Request.
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activeresource-5.1.0/lib/active_resource/connection.rb:141:in `handle_response'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activeresource-5.1.0/lib/active_resource/connection.rb:126:in `request'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activeresource-5.1.0/lib/active_resource/connection.rb:85:in `block in get'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activeresource-5.1.0/lib/active_resource/connection.rb:220:in `with_auth'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activeresource-5.1.0/lib/active_resource/connection.rb:85:in `get'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activeresource-5.1.0/lib/active_resource/base.rb:1073:in `find_every'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activeresource-5.1.0/lib/active_resource/base.rb:974:in `find'
    from (irb):6
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/railties-5.0.3/lib/rails/commands/console.rb:65:in `start'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/railties-5.0.3/lib/rails/commands/console_helper.rb:9:in `start'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:78:in `console'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/railties-5.0.3/lib/rails/commands.rb:18:in `<main>'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/bootsnap-1.0.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:17:in `require'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/bootsnap-1.0.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:17:in `require'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:293:in `block in require'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:259:in `load_dependency'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:293:in `require'
    from /Users/bebble1/work/awe/bin/rails:9:in `<main>'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/bootsnap-1.0.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `load'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/bootsnap-1.0.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `load'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:287:in `block in load'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:259:in `load_dependency'
    from /Users/bebble1/.rvm/gems/ruby-2.3.0/gems/activesupport-5.0.3/lib/active_support/dependencies.rb:287:in `load'
    from /Users/bebble1/.rvm/rubies/ruby-2.3.0/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /Users/bebble1/.rvm/rubies/ruby-2.3.0/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb:54:in `require'

I have also attached a picture here of the outcome from Rails app

It seems like you are not authenticating with Rails app. And I am sure you have set authentication username/password in Postman.

Set self.password = "password" (use your own password) to PayRunEmploymentHeroBase and it will work.

Update: It's actually your url is not encoded, do this and it will solve the issue:

self.prefix = "/api/v2/business/:business_id/payrun?$filter=" + URI::encode("DateFinalised gt datetime':finalised_date'")