Description
Currently, when a user attempts to send an empty message, the validation error "Please enter your message" appears. However, this error message persists even when the user starts typing in the input field. It remains visible until a valid message is actually sent, even if the widget is minimized and restored.

Steps to Reproduce

1. Open the chat widget.
2. Leave the message input field empty.
3. Click the "Send" button (or press Enter).
4. The error message "Please enter your message" appears.
5. Start typing a message (e.g., "Hello...").

Current Behavior
The validation error remains visible while the user is typing. It does not disappear until the message is successfully sent.

Expected Behavior
The error message should disappear immediately as soon as the user starts typing (on input or keydown event). This would provide a better user experience (UX).