Welcome to Microsoft Q&A platform and thanks for posting your question here.
To delete the resource group, you need to remove the deny assignment that is blocking the deletion. you can do this by signing in to the Azure portal, navigating to the resource group, clicking on the "Access control (IAM)" tab, searching for the deny assignment with the specified name and ID, and then deleting it. If you are unable to remove the deny assignment, you should contact your Azure administrator or the owner of the subscription to grant them the necessary permissions.
Reference
https://learn.microsoft.com/en-us/azure/role-based-access-control/deny-assignments?tabs=azure-portal#list-deny-assignments
https://learn.microsoft.com/en-us/azure/azure-resource-manager/management/delete-resource-group?tabs=azure-powershell
Hope this helps. Do let us know if you any further queries.
If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.