You can use iCloud from anywhere by signing in to iCloud.com from a web browser recommended in the Apple Support article System requirements for iCloud.
Sign in to iCloud.com
If you’re already signed in to your device with your Apple ID and your device has Touch ID or Face ID, you can use it to sign in to iCloud.com.
If you set up two-factor authentication or two-step verification, follow the onscreen instructions to verify your identity by entering a code sent to a trusted device.
If you’ve lost your trusted device, you can still use Find My iPhone by clicking the Find iPhone button after you enter your Apple ID. See How to sign in to Find My iPhone on iCloud.com.
For troubleshooting tips, see Trouble signing in to iCloud.com.
Apps and features on iCloud.com
You can use iCloud.com to view information stored in iCloud from a web browser. Learn what you can do with the following apps and features on iCloud.com on a computer:
If you don’t see an app you’re looking for, you may not be able to view it online, or you may need to access iCloud.com on a different device. See the Apple Support article Which iCloud.com features are available in the browser on your device.
If you have web-only access to iCloud.com, you only see Contacts, iCloud Drive, Keynote, Notes, Numbers, and Pages. To see and use other iCloud features, set up iCloud on an iPhone, iPad, iPod touch, or Mac. To learn more about web-only access, see the Apple Support article Web-only access to iCloud.
Switch to a different iCloud.com feature
At the top of the iCloud.com window, click the name of the feature you’re currently using, then click another feature.
Sign out of iCloud.com
Do one of the following:
Sign out from the browser you’re using now: Click your name at the top of the iCloud.com window, then choose Sign Out.
Sign out from every browser where you’re currently signed in: Go to Settings on iCloud.com, click Sign Out Of All Browsers (in the Advanced section), then click Sign Out.