Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
From Microsoft, you can only get the most recent version of Outlook which is Outlook 2024. See https://www.microsoft.com/en-us/microsoft-365/p/outlook/cfq7ttc0pbmd.
Getting just one Office application is rather expensive, though. If you need Word, Excel and PowerPoint too, Office Home & Business may be a better option. See https://www.microsoft.com/en-us/microsoft-365/p/office-home-business-2024/cfq7ttc0pbm7.
Both of these one-time payment versions are for one user and one computer (PC or Mac).
Note that there is also a free version of Outlook, the so-called new Outlook, which replaces Windows Mail. This version can be downloaded from the Microsoft Store. (Keep in mind that the new Outlook has limited capabilities compared to the classic version which is part of Microsoft Office.)