// source https://jsbin.com

jsbin.untitled.js

let element = document.querySelector('#auto-complete');
let uri = 'https://example.org/search';
let choice = new Choices(element, {
    removeItemButton: false,
    itemSelectText: '',
    shouldSort: false,
});
let timer = null;

choice.passedElement.addEventListener('search', function (event) {
    if (event.detail.value.length > 3) {
        
        if (null !== timer) {
            clearTimeout(timer);
        }

        timer = setTimeout(function () {

            let request = new Request(uri + "?term=" + event.detail.value, {
                credentials: 'same-origin',
            });

            fetch(request)
                .then(function (response) {
                    if (200 === response.status) {
                        response.json().then(function (data) {
                            choice.setChoices(data, 'id', 'label', true);
                        });
                    }
                })
                .catch(function (error) {
                    console.log(error);
                })
            ;
        }, 1000);
    }
});