No Web Page item type??
It seems that I am just expected to install a browser extension to create a web page item in Zotero, but I am not permitted to install browser extensions on my computer. Why not have a manual way to add Web Page items? Why make it so confusing?
Upgrade Storage
https://www.zotero.org/support/adding_items_to_zotero#via_your_web_browser
It's a core part of Zotero functionality.
From a security perspective, it doesn't make a ton of sense for an organization to allow arbitrary desktop apps to be installed but disallow all browser extensions, given that desktop apps can generally do more, and in a harder-to-detect manner.
If you really can't install the Connector, you can just create a new item of another type and change the item type, as explained here:
https://www.zotero.org/support/adding_items_to_zotero#manually_adding_items
But it'd be better to ask your IT department to allow you to install the Connector.