can i upgrade my icloud storage of iphone through pc

You can certainly upgrade your iCloud storage plan using your iPhone (Settings > [your name] > iCloud > Manage Storage), but it seems you can also do this on a Windows PC if you have installed iCloud for Windows. Obviously I can't test this for you.

On the linked page Apple advises under the paragraph Manage your iCloud storage usage and account information: "If you want to make changes to your Apple ID, including updating your email, mailing address, or other account information, open iCloud for Windows and click Account details. Click Manage Apple ID."