Till this period of time, the Pre-order app system has not been added the function of capturing the payment on the site. However, you can capture the payment of products automatically or manually as Shopify’s instruction:
At this point, you will have an authorization period of 7 days to capture the payment. In case you are using the function of Partial payment when the clients pre-order a product, the app will automatically send an email to remind them to fulfill the rest of their payment after 7 days and they will check out to make a payment once more time.
At the second time of payment, there will be no transaction fee because the fee has been completed in the 1st payment
In case you struggle with any steps while capturing the payment, please get in touch with Shopify support team for more details