TextMeshPro input field script input at caret position

In VR I have a virtual keyboard to allow users to type text. I want to use a Textmeshpro Input field for the text to be written. Is there a way to insert text at the caret position?

So far I can do it 'manually': get the text and the caret position, insert the character, and replace the text of the input field. But updating the caret position doesn't seem to work then.