Please note that this is an expected behavior, as this site has third-party icons. If you want to add more icons, please try installing the FontAwesome plugin. All other options will require custom implementation, which means connecting third-party libraries.
I see. Sorry for the confusion. If you are referring to emojis (those that can be copied as text), and not icons with images, then please note that each system uses its own emojis, for example, MacOS has one style and Windows has another, but the meaning of these emojis is the same, only the styles are different.