Ruby on Rails Paypal REST API guest checkout -

i'm trying debug rails app developer. keep in mind have little experience both ruby , rails. goal allow users pay credit card when go paypal payment page without need registration.

the actual code in model/shopping-card.rb is:

include paypal::sdk::rest  class shoppingcart   def initialize(session)     @session = session     @session["delivery"] ||= "shipping"     @session[:coupon] ||= {"token" => nil, "discount" => nil}     @session[:shopping_cart] ||= []   end    def delivery=(v)     @session["delivery"] = v   end    def delivery     @session["delivery"]   end    def should_add_shipping_costs?     @session["delivery"] == "shipping"   end    def cart     @session[:shopping_cart]   end    def discount     val = @session["coupon"]["discount"]     if val.nil?       nil     else       val.to_f     end   end    def token     @session["coupon"]["token"]   end    def coupon=(c)     @session["coupon"]["token"] = c.try("token")     @session["coupon"]["discount"] = c.try("discount")   end    def subtotal_discount     subtotal.to_f / 100 * discount.to_f   end    def subtotal_after_discount     [(subtotal.to_f - subtotal_discount), 0].max   end    def subtotal_after_discount_with_vat     subtotal_after_discount + subtotal_after_discount / 100 * 21   end    def add(product, quantity)     quantity = quantity.to_i      index = cart.find_index |item|       item["id"] == product.id     end      # not in chart     if index.nil?      item = product.to_cart      item[:quantity] = quantity      cart << item     else       item = cart[index]       item["quantity"] = item["quantity"].to_i + quantity     end   end    def remove(id)     cart.delete_if |item|       item["id"].to_s == id.to_s     end   end    def clear     cart.clear   end    def each(&block)     cart.each(&block)   end    def each_with_index(&block)     cart.each_with_index(&block)   end    def empty?     cart.empty?   end    def to_paypal     f = cart.map |item|       {         name: item["name"],         price: "%.2f" % item["price_or_promo"],         quantity: item["quantity"],         currency: "eur",       }     end     f   end    def subtotal     amount = 0     each |item|       amount += item["price_or_promo"].to_f * item["quantity"].to_i     end     "%.2f" % amount   end    def total_iva     subtotal.to_f * 0.21   end    def total_for(user)     t = subtotal_after_discount.to_f + total_iva + surcharge_for(user)     if self.should_add_shipping_costs?       t + shipping_cost     else       t     end   end     def surcharge_for(user)     user.surcharge ? subtotal.to_f * 0.052 : 0   end    def shipping_cost     total = 0     each |item|       total += (item['shipping'].to_f * item['quantity'].to_i)     end     total   end    def create_payment(description, user)     payment = payment.new({       :intent => :sale,       :payer => {         :payment_method => :paypal       },        :redirect_urls => {         :return_url => env['paypal_return_url'],         :cancel_url => env['paypal_cancel_url']       },        :transactions => [{         :item_list => {           :items => {             :name => description,             :price => "%.2f" % total_for(user),             :quantity => 1,             :currency => "eur"           }         },          :amount => {           :total => "%.2f" % total_for(user),           :currency => "eur"         },           :description => description       }],     })      if payment.create       @session[:payment_id] = payment.id     end      payment   end    def build_order     order = order.new(user_id: @session[:user_id])     each |item|       order.operations << operation.new(         product_id: item["id"],         quantity: item["quantity"].to_i       )     end      order   end    def complete_payment(params)     payment = payment.find(@session[:payment_id])     if payment.execute(payer_id: params[:payerid])       build_order.save!       @session[:payment] = nil       @session[:coupon] = nil       clear     end      if(coupon = coupon.find_by(token: token))       coupon.used = true       coupon.save!     end     payment   end  end 

and in controllers/payment-controller.rb

include paypal::sdk::rest  class paymentscontroller < applicationcontroller   def checkout     @payment = shopping_cart.create_payment("cultius purchase", current_user)     if @payment.success?       redirect_to @payment.links.find{|v| v.method == "redirect" }.href     else       logger.error "error while creating payment:"       logger.error @payment.error.inspect     end   end    def success     shopping_cart.complete_payment(params)   end end 

so finally, speaking pp credit card option hast enabled checking option on pp account settings. option 'elegible buyers'.