<div>
<select id="city">
<option value="" selected>Chọn tỉnh thành</option>           
</select>
          
<select id="district">
<option value="" selected>Chọn quận huyện</option>
</select>
<select id="ward">
<option value="" selected>Chọn phường xã</option>
</select>
 </div> 
        <h2 id="result"></h2>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js" referrerpolicy="no-referrer"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/axios/0.21.1/axios.min.js"></script>
    <script>
    const host = "https://provinces.open-api.vn/api/";
var callAPI = (api) => {
    return axios.get(api)
        .then((response) => {
            renderData(response.data, "city");
        });
}
callAPI('https://provinces.open-api.vn/api/?depth=1');
var callApiDistrict = (api) => {
    return axios.get(api)
        .then((response) => {
            renderData(response.data.districts, "district");
        });
}
var callApiWard = (api) => {
    return axios.get(api)
        .then((response) => {
            renderData(response.data.wards, "ward");
        });
}
var renderData = (array, select) => {
    let row = ' <option disable value="">Chọn</option>';
    array.forEach(element => {
        row += `<option data-id="${element.code}" value="${element.name}">${element.name}</option>`
    });
    document.querySelector("#" + select).innerHTML = row
}
$("#city").change(() => {
    callApiDistrict(host + "p/" + $("#city").find(':selected').data('id') + "?depth=2");
    printResult();
});
$("#district").change(() => {
    callApiWard(host + "d/" + $("#district").find(':selected').data('id') + "?depth=2");
    printResult();
});
$("#ward").change(() => {
    printResult();
})
var printResult = () => {
    if ($("#district").find(':selected').data('id') != "" && $("#city").find(':selected').data('id') != "" &&
        $("#ward").find(':selected').data('id') != "") {
        let result = $("#city option:selected").text() +
            " | " + $("#district option:selected").text() + " | " +
            $("#ward option:selected").text();
        $("#result").text(result)
    }
}
	</script>