Currently you can buy an additional year of licensing for R1,199 for family & R999 for Personal from the links below. Or do a search to see if there are better prices around.
Each license you add to your Microsoft account extends your license by a year, you can add multiple licenses to extend for multiple years.
How do I add the License to my account
https://www.handshake.co.za/2025/adding-microsoft-license-key-to-your-365-account/