A Microsoft file hosting and synchronization service.
Hello
If you go to www.onedrive.com > Sign into the correct account, does it show 1TB?
If it doesn't, you need to contact Microsoft support because the provision can be wrong.
To get help, open the "Get Help" app on your computer (just search for it in the Start menu). or go to https://support.microsoft.com/contactus, Type "Billing" and press Enter. On the next screen, click "Contact support" at the bottom of the page, then choose "Microsoft 365" > "Manage my subscription". You’ll then see the option to chat with a Microsoft support agent who has access to your account to help review the issue.