Texts that come from other themes, plugins, widgets, and buttons don't always appear in String Translation. In such scenarios, you don't need to scan your theme or plugin to find the strings. But, the steps you need to take depend on the type of string you want to translate.
For example, the steps you need to take to translate button text like the "Add to cart" button are different than the steps to translate settings, options, or email texts from themes or plugins.
