There is a preinstalled on-screen keyboard app in your set which will appear whenever text is expected to be entered by the user, e.g., Wi-Fi password or website address in the web browser.
To navigate the on-screen keyboard, use the arrow buttons on the remote control, enter the character selected by pressing OK.
Press and hold OK button for 2 seconds on selected symbol to invoke associated national character(s) (with accents or diacritical marks).