Where to download the full installer of Microsoft office 365 download?

Trying to set up Microsoft Office 365 on my new PC with a slow internet, so the little web-based installer that downloads everything piece by piece isn't going to cut it . I need the full package upfront so I can install Office on my Windows 11 PC in one go without constant re-downloading if the connection drops.

Anyone know the proper way to download Microsoft Office 365 offline installer for PC? I want to make sure I'm going through a legitimate channel tied to an actual license/account rather than some random link, so pointers to the right official process would be great. 

P.S It should be working fine on both Windows 11 and Windows 10.