Hi,
When signed in to the Azure portal as a Global Administrator, please select Yes under Azure Activate Directory -- Properties (link below) -- Access management for Azure resources, and click Save:
https://portal.azure.com/#view/Microsoft_AAD_IAM/ActiveDirectoryMenuBlade/~/Properties
Next sign out of the portal, sign back in, and then assign yourself Owner role to the subscription via <yourSubscription> -- Access control (IAM) -- Add. Sign out and back in and verify that you have Owner rights. You should be able to give your contractor the permissions they need.
If the above is useful please click Accept Answer.
Thanks.
-TP