Apples build in Emoji Keyboard has a section with "Memoji" stickers. If you tap on any of these stickers (it seems to be a PNG image), then it's automatically inserted into the textfield or into the chat of the current App, for example WhatsApp, Facebook Messenger or iMessage.
![WhatsApp with Memoji](https://i.stack.imgur.com/pRry8.png)
Is it possible to get the same functionality with a custom keyboard? Or is Apple using some private API for the Memoji stickers?
I know how to add an image or image data to the pasteboard like UIPasteboard.general.image or UIPasteboard.general.setData(...). But if I do so, the png image isn't pasted automatically into the textfield. The user has to do additional steps and tap with the finger into the textfield and select "paste".