Intergrate PayPal checkout with Kivy app?

I was wondering if it is possible to integrate a PayPal checkout into my kivy app? I want the total to be determined based on a variable in my python kivy code named cart. So far, I haven’t seen anything online with this subject. Any help would be appreciated!

I have this simple code that can describe more what I want to achieve

.py

from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.screenmanager import Screen, ScreenManager ,SlideTransition
from kivy.properties import NumericProperty
import webbrowser

y = 0.20
class MenuScreen(Screen):
    def item1(self):
        global y
        y -= 0.02
        App.get_running_app().cart += 7
        App.get_running_app().root.get_screen("cart").add_widget(Label(text="Item 1", font_size=20, pos_hint={"x": 0, "y": y}))

class CartScreen(Screen):
    def PayPal(self):
        webbrowser.open_new_tab("PayPal.html")
    
    def menu(self,button):
        self.manager.transition = SlideTransition(direction="right")
        self.manager.current = "menu"

class WindowManager(ScreenManager):
    pass

class ExampleApp(App):
    cart = NumericProperty()
    def build(self):
        return WindowManager()

if __name__ == "__main__":
    ExampleApp().run()

.kv

#:import SlideTransition kivy.uix.screenmanager.SlideTransition

<WindowManager>:
    MenuScreen:
    CartScreen:

<MenuScreen>:
    name: "menu"

    FloatLayout:
        Label:
            text: "MENU"
            font_size: 40
            pos_hint: {"x": 0, "y": 0.3}
        Label:
            text: "$ " + str(app.cart)
            font_size: 20
        Button:
            text: "Add to cart"
            size_hint: 0.3,0.08
            pos_hint: {"x": 0.5, "y": 0.3}
            on_release:
                root.item1()
        Button:
            text: "Cart"
            size_hint: 0.3,0.08
            pos_hint: {"x": 0.5, "y": 0.2}
            on_release:
                app.root.transition = SlideTransition(direction = "right")
                app.root.current = "cart"

<CartScreen>:
    name: "cart"

    FloatLayout:
        Label:
            text: "CART"
            font_size: 40
            pos_hint: {"x": 0, "y": 0.3}
        Label:
            text: "$ " + str(app.cart)
            font_size: 20
        Button:
            text: "PayPal Checkout"
            size_hint: 0.3,0.08
            pos_hint: {"x": 0.5, "y": 0.3}
            on_release:
                root.PayPal()
        Button:
            text: "Back"
            size_hint: 0.3,0.08
            pos_hint: {"x": 0.5, "y": 0.2}
            on_release:
                app.root.transition = SlideTransition(direction = "left")
                app.root.current = "menu"

PayPal HTML file

<div id="smart-button-container">
    <div style="text-align: center"><label for="description"> </label><input type="text" name="descriptionInput" id="description" maxlength="127" value=""></div>
      <p id="descriptionError" style="visibility: hidden; color:red; text-align: center;">Please enter a description</p>
    <div style="text-align: center"><label for="amount"> </label><input name="amountInput" type="number" id="amount" value="" ><span> CAD</span></div>
      <p id="priceLabelError" style="visibility: hidden; color:red; text-align: center;">Please enter a price</p>
    <div id="invoiceidDiv" style="text-align: center; display: none;"><label for="invoiceid"> </label><input name="invoiceid" maxlength="127" type="text" id="invoiceid" value="" ></div>
      <p id="invoiceidError" style="visibility: hidden; color:red; text-align: center;">Please enter an Invoice ID</p>
    <div style="text-align: center; margin-top: 0.625rem;" id="paypal-button-container"></div>
  </div>
  <script src="https://www.paypal.com/sdk/js?client-id=sb&currency=CAD" data-sdk-integration-source="button-factory"></script>
  <script>
  function initPayPalButton() {
    var description = document.querySelector('#smart-button-container #description');
    var amount = document.querySelector('#smart-button-container #amount');
    var descriptionError = document.querySelector('#smart-button-container #descriptionError');
    var priceError = document.querySelector('#smart-button-container #priceLabelError');
    var invoiceid = document.querySelector('#smart-button-container #invoiceid');
    var invoiceidError = document.querySelector('#smart-button-container #invoiceidError');
    var invoiceidDiv = document.querySelector('#smart-button-container #invoiceidDiv');

    var elArr = [description, amount];

    if (invoiceidDiv.firstChild.innerHTML.length > 1) {
      invoiceidDiv.style.display = "block";
    }

    var purchase_units = [];
    purchase_units[0] = {};
    purchase_units[0].amount = {};

    function validate(event) {
      return event.value.length > 0;
    }

    paypal.Buttons({
      style: {
        color: 'black',
        shape: 'rect',
        label: 'checkout',
        layout: 'vertical',

      },

      onInit: function (data, actions) {
        actions.disable();

        if(invoiceidDiv.style.display === "block") {
          elArr.push(invoiceid);
        }

        elArr.forEach(function (item) {
          item.addEventListener('keyup', function (event) {
            var result = elArr.every(validate);
            if (result) {
              actions.enable();
            } else {
              actions.disable();
            }
          });
        });
      },

      onClick: function () {
        if (description.value.length < 1) {
          descriptionError.style.visibility = "visible";
        } else {
          descriptionError.style.visibility = "hidden";
        }

        if (amount.value.length < 1) {
          priceError.style.visibility = "visible";
        } else {
          priceError.style.visibility = "hidden";
        }

        if (invoiceid.value.length < 1 && invoiceidDiv.style.display === "block") {
          invoiceidError.style.visibility = "visible";
        } else {
          invoiceidError.style.visibility = "hidden";
        }

        purchase_units[0].description = description.value;
        purchase_units[0].amount.value = amount.value;

        if(invoiceid.value !== '') {
          purchase_units[0].invoice_id = invoiceid.value;
        }
      },

      createOrder: function (data, actions) {
        return actions.order.create({
          purchase_units: purchase_units,
        });
      },

      onApprove: function (data, actions) {
        return actions.order.capture().then(function (details) {
          alert('Transaction completed by ' + details.payer.name.given_name + '!');
        });
      },

      onError: function (err) {
        console.log(err);
      }
    }).render('#paypal-button-container');
  }
  initPayPalButton();
  </script>

Answer

PayPal and similar services has an api which you should be able to communicate with using kivy.network.urlrequest module. Or other option is to use Checkout-Python-SDK refer to the link https://github.com/paypal/Checkout-Python-SDK.