Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Here's your options:
- set up the 2 office 365 keys with 1 Microsoft Account (office.com/setup) so that instead of just 1 year of subscription it will be for 2 years subscription (which is a subscription "stacking").
- set up the 2 office 365 keys with 2 separate Microsoft Account if you want to have more installations available.