Easy! Simply click on the "Add gadget" button at the top right of your JIRA Cloud dashboard and search for "Calculated".
In the top right of your gadget you'll see 3 dots. Click this and select "Edit" from the resulting dropdown menu.
This will modify the top title to display on the gadget. It is flexible and can be left blank if desired to fit your naming and versioning convention.
This is the most important field to populate for the gadget to be used. This field should be populated with the JQL statement that returns the task(s) that represent your release/deployment/project that you would like to track.