Disable send button when message input box is having message of length > 4

[Subbu-git-coder]

I'm using "react-chatbot-kit": "2.2.2".
I would like to load chatbot with disabled "Send button".
Once user entered input that is more than 4 chars, then the send button should be enabled.
I have added a validator to "Chatbot" tag. So that message of length < 5 wont be posted.
But, how to update Send button status or CSS?
The validator code is;

const Validator = (input) => { if (input.length > 4) return true; return false } export default Validator;