How do you find an AirTag on the web How do you find an AirTag on the web using iCloud.com's FindMyiPhone (not the app?)
AirTags can only be tracked with Find My app, either on an iPhone/iPad or Mac - but not on the web.
Instructions from Apple for locating and AirTag:

Open the Find My app, then tap the Items tab.
Choose the AirTag you want to locate in the Items list.

https://support.apple.com/en-us/HT210967