faraday.rb

def call
  # code omitted
  
  res = Connection.internal_api.get do |req|
    req.url "#{ENV['TRANSACTION_HOST']}/transactions?user_id=#{user_id}"
    req.headers['UserRole']    = 'new_value'
    req.headers['OtherHeader'] = 'other_value'
  end
  
  # code omitted
end