How to open Shopify checkout and payment options

[abhishekraics001]

I am facing difficulty adding items in the cart as not finding the right way to get checkout. If someone helps me to get it done it's proud.

[abhishekraics001]

Below is the list of methods but not getting checkoutIDs out of them and i need help on an urgent basis. i will pay for same

ShopifyCheckout shopifyCheckout = ShopifyCheckout.instance;
Future getCheckoutInfoQuery({String checkoutId})
Future getCheckoutInfoWithAvailableShippingRatesQuery({String checkoutId})
Future<List> getAllOrders({String customerAccessToken})
Future checkoutLineItemsReplace({String checkoutId, List<Map<String,dynamic>> checkoutLineItems})
Future checkoutCustomerAssociate({String checkoutId, String customerAccessToken})
Future checkoutCustomerDisassociate({String checkoutId})
Future checkoutDiscountCodeApply({String checkoutId, String discountCode})
Future checkoutDiscountCodeRemove({String checkoutId})
Future createCheckout()
Future checkoutGiftCardAppend(String checkoutId, List giftCardCodes)
Future checkoutGiftCardRemove(String appliedGiftCardId, String checkoutId)
Future shippingLineUpdate(String checkoutId, String shippingRateHandle)
Future checkoutCompleteFree(String checkoutId)
Future updateAttributes(String checkoutId, {bool allowPartialAddresses, Map<String, String> customAttributes, String note})