Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Since Office 2013 isn’t available for direct public download anymore, you can reinstall it is through the Microsoft account that originally redeemed or activated the product key. That’s where your license is stored. Do you still have access to the Microsoft account used when you activated Office 2013? Do you still have the 25 character product key?