Go to the "Variables" section of the blocks palette, select "Make a Variable", and then click the checkbox next to "Cloud variable (stored on server)". The data associated with your cloud variable will be stored on the server, preserved over time, and accessible to anyone who opens the project.
There are a couple of reasons cloud variables may not appear in your editor:
- If you are a new Scratcher, cloud variables will be disabled on your account until you obtain Scratcher Status. You can obtain this status by being active in the community and waiting for an invitation to become a Scratcher.
- If you are running Scratch on an Android, cloud variables are disabled for your device.