How To Encode UTF-8 to Tis-620 or Windows874

[mafxgaaa]

CMD:twa(playerid, params[])
{
cef_hide_browser(playerid, INTERFACE_AREATBOX_ID, false);
cef_emit_event(playerid, "interface:Arertbox", CEFSTR(params));
SendClientMessageEx(playerid, COLOR_RED, params);
return 1;
}

cef.on("interface:Arertbox", (text) => {
document.getElementById("Arertbox").innerText = ${text};
});

how to encode i use win874