Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
This is article about sharing your subscription: https://support.microsoft.com/en-us/office/share-your-microsoft-365-family-or-premium-subscription-b389b9ce-3ae3-4a82-9017-39d79972fcba
When you share your subscription, other user has to accept it.
Go to https://account.microsoft.com/services/microsoft365/details and under "Share subscription" (click on it to open) you should see list of people you have shared your subscription with. Check if the other user accepted invitation or invitation is pending. If necessary, resend invitation.