want to add new computer to my subscription paid

If the subscription is Microsoft 365 Family, it can be shared with up to five other people in the household at no extra cost. To add the husband’s account:

1. Sign in to the Microsoft account, Sharing page using the same Microsoft account that owns the Microsoft 365 Family subscription.
2. On the Sharing tab, select Start sharing.
3. In the Share Office pop-up, choose one of these options:
   • Invite via email: enter the husband’s email address and select Invite. The invited person should use that same email address for the shared Microsoft 365 subscription.
   • Invite via link: copy the link and send it by message. When the recipient opens the link and signs in with a Microsoft account, that account is added to the subscription.
4. After accepting the invitation, install Microsoft 365 on the new computer by signing in at the Microsoft 365 portal and selecting Install apps.

Important details:

• A Microsoft account can have only one active Microsoft 365 subscription.
• Adding the same subscription to the account extends the subscription time; it does not increase storage or device sign-in limits.
• Microsoft 365 can be signed in on five devices at the same time. If more than five devices are signed in, the first device is signed out automatically.
• If the subscription is Microsoft 365 Personal, the context does not provide a way to share it with another person.

References:

• How to share your Microsoft 365 Family subscription
• Manage Microsoft 365 subscription sharing
• What happens if I add another Microsoft 365 for home subscription to my account?