Normally, the order status of the payment in wallee and in Shopify should be synchronized automatically. However, it can always be that due to unforeseen circumstances this is not the case. In this case, you can manually re-send the notifications to Shopify.
Manually send the webhook requests from wallee to Shopify
Search for your transaction inside wallee. This can be done via Payments > Transactions. If you want to search by the order name of Shopify you go to Shopify > Transaction. Make sure you add the Column order name.
Open the transaction, here you directly see in the overview if the synchronization was successful. If you open the transaction now, you are able to resend the notification to Shopify by clicking on "Resend".
In the lower end of the screen, you can also see a log of the notifications and if they were successfully delivered. In case the delivery is not possible, you will also find additional details in the log.