'callus' namespace should be used when defining localization strings for CallUs plugin in your i18n JSON file.
In the example below, we demonstrate defining new strings for the 'en' (English) language. You may use any language codes you wish; there is no standard format. When selecting the active language in your configuration, you must match one of the language codes defined in your i18n JSON file. Please note that you must only define a language code once in your i18n JSON file. Inside each language object you should define new strings for each widget.
Example i18n JSON