I am running latest stable version of LibreElec, sending text to Kodi does not work from the web interface or by using Kore remote.
I have also tried running this command:
curl -v -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","method":"Input.SendText","params":{"text":"<text to send>","done":false},"id":1}' http://<host>:<port>/jsonrpc
it says it sent ok, but nothing is displayed?