Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
The StackBlockedDueToOrderPendingChangeRecord error indicates there is a pending subscription change, billing details update, or active subscription order blocking the Microsoft 365 setup or product key redemption, this forum is a user to user forum, no-one here has any account access, you will need to contact Microsoft Support directly, try using this method to contact their support.
Go to this link: https://support.microsoft.com/contactus
Select Microsoft 365
Click 'Get Home Support'.
In the box provided, type billing.
Press Enter, then on the next page, scroll down and click 'Sign in to Contact Support'.
Navigate to Microsoft 365 and Office - Manage my Subscription.
Select the 'Chat with support agent in web browser' option