Do you need a Macbook to upload videos to your iCloud library or does it work with a PC as well?

Hello!

I've been using iPhone since 2010 but at that age I was too stupid to have an iCloud with extra storage, so every time I got a new phone, I downloaded my photos from the old iPhone to PC and then to an external hard drive.

So I got photos stored from way back and now I got 2TB storage on my iCloud and I would like to upload all of these videos and photos to my iCloud so that I got it all gathered on my iCloud so that it's possible to find it all on my iPhone Photos app.

I've tried to use the iCloud.com website and upload through there, but for some reason that website only accepts JPEG-files which means that no videos are added.

When I go through the iCloud for Windows app there is an alternative to sync my PC-pictures on iCloud to be able to reach them from all my units, but the problem is that there's so many photos so I cant even fit them in a map on my computer, that's why I have to store them on a hard drive.

So one question is: Is it possible to choose a map on my external drive to have as my iCloud map on my PC? I think the answer is no?

My second question: Is there anyway to upload the videos to this map, then delete it from the map on the PC and still keep it in the iCloud storage through the cloud so that it's reachable from my iPhone? I will still have a backup on my external hard drive. I think the answer to this is also no?

My third question: Is there any way at all to upload things to your iCloud through a file on a hard drive or a PC or a Macbook without having it synced on my PC/Macbook?

I've been trying to solve this for years with my PC and I would honestly transfer some money to the person that could help me with a solution for this because I've been trying so many different things, researched so wide and I'm starting to think that there's absolutely no way to get this fixed.