Since Claro is a web-based tool, you can use the built-in spell checker that comes with most browsers.
Open a text element for editing by double clicking on it. Hold Control (Command on Mac) and right-click. From the pop-up menu, select Spelling and Grammar.
You can usually set the spell checker to check as you type or turn this feature off. Open your browser Tools, Options, or Preferences to set these features.
If your browser doesn’t have a built-in spell checker (Internet Explorer does not), install a spell checker plugin such as Speckie.