JSFiddle - React, Tailwind, and code Playground

HTML

<select name="billing_country" id="billing_country" class="country_to_state country_select select2-hidden-accessible" autocomplete="country" data-placeholder="Select a country / region…" tabindex="-1" aria-hidden="true"><option value="">Select a country / region…</option><option value="AF">Afghanistan</option><option value="AX">Åland Islands</option><option value="AL">Albania</option><option value="DZ">Algeria</option><option value="AS">American Samoa</option><option value="AD">Andorra</option><option value="AO">Angola</option><option value="AI">Anguilla</option><option value="AQ">Antarctica</option><option value="AG">Antigua and Barbuda</option><option value="AR">Argentina</option><option value="AM">Armenia</option><option value="AW">Aruba</option><option value="AU">Australia</option><option value="AT">Austria</option><option value="AZ">Azerbaijan</option><option value="BS">Bahamas</option><option value="BH">Bahrain</option><option value="BD">Bangladesh</option><option value="BB">Barbados</option><option value="BY">Belarus</option><option value="PW">Belau</option><option value="BE">Belgium</option><option value="BZ">Belize</option><option value="BJ">Benin</option><option value="BM">Bermuda</option><option value="BT">Bhutan</option><option value="BO">Bolivia</option><option value="BQ">Bonaire, Saint Eustatius and Saba</option><option value="BA">Bosnia and Herzegovina</option><option value="BW">Botswana</option><option value="BV">Bouvet Island</option><option value="BR">Brazil</option><option value="IO">British Indian Ocean Territory</option><option value="BN">Brunei</option><option value="BG">Bulgaria</option><option value="BF">Burkina Faso</option><option value="BI">Burundi</option><option value="KH">Cambodia</option><option value="CM">Cameroon</option><option value="CA">Canada</option><option value="CV">Cape Verde</option><option value="KY">Cayman Islands</option><option value="CF">Central African Republic</option><option value="TD">Chad</option><option...

JavaScript

function checkIfInternational(e) {
  console.log(e); 
}
const shipCountry = document.querySelector("#billing_country");

shipCountry.addEventListener("change", checkIfInternational);