JSFiddle - React, Tailwind, and code Playground

HTML

<input id="autocomplete" />

JavaScript

var options = ['@gmail.com', '@msn.com', '@yahoo.com'];
$("input#autocomplete").autocomplete({
    source: options
});
$("input#autocomplete").keyup(function() {
    var new_options = [];
    for (var i = 0; i < options.length; i++)
        new_options[i] = $(this).val() + options[i];
    $(this).autocomplete( "option", "source", new_options);
});