Blackbaud checkout create transaction issue

Hi @Erik Leaver : Thank you for your response. I am following steps mentioned in above video.
Please refer more details related to my api work flow.

1)Donor selects amount in donation page.
2)Blackbaud checkout popup open
3)Donor select apple pay payment
4)Donor enter real card details and submit

API calls:

function onDonateNowClicked(sender, args) {

  // append any donor-entered information to the transaction obejct

  var amt = $('#' + '<%= txtamount.ClientID %>').val();


  var transactionData = {

      'key': '<key>',

      'payment_configuration_id': '<payment_configuration_id>',

      'amount': amt,

      'client_app_name': '<client_app_name>',

      'security_token': '<security_token>',

      'is_offline': true,

      'use_apple_pay': true,

      'use_apple_pay_donate_button': true

  };



  // call the Checkout method to display the payment form

  Blackbaud_OpenPaymentForm(transactionData);

  args.set_cancel(true); // Cancel default postback

}

<script src="https://payments.blackbaud.com/Checkout/bbCheckout.2.0.js"></script>

i got token also from checkoutComplete event.

Next I am calling transaction API
https://api.sky.blackbaud.com/payments/v1/checkout/transaction

with amount and checkoutComplete event token.

At that time api gives error Transaction is required.

Please help me to resolve this with priority.

@Erik Leaver : I have tried with both way.
For blackbaud checkout i am getting error transaction is require as mention above.
For blackbaud new checkout it seems that sample repo is bit different with API doc.

https://developer.sky.blackbaud.com/api#api=payments&operation=CaptureTransaction

In sample repo:
// Capture the payment
await fetch(${_baseUrl}/checkouttransactions/capture, {
method: "POST",
headers: {
"Content-Type": "application/json",
},
body: JSON.stringify({
amount: amount,
transaction_token: transactionToken,
card_token: cardToken,
payment_configuration_id: transactionData.payment_configuration_id,
}),

where as in document:

Request

https://api.sky.blackbaud.com/payments/v1/transactions/{transaction_id}/capture

Request parameters

NameInRequiredTypeDescriptiontransaction_idtemplatetruestring

The identifier of the authorized transaction you would like to capture.

So transaction_id is missing in sample repo.

Help me with this.

@Erik Leaver :First I open blackbaud checkout form using  payment configuration ID.
After that select apple pay payment option, add card details and click on process/payment.

So i get transaction token from checkout complete event.

I use that transaction token and amount and oauth access token to perform Create checkout transaction.

reference link:https://developer.blackbaud.com/skyapi/products/bbms/payments/integrations/checkout/process-overview