Ошибка в gulp с плагином

Выдаёт ошибку в консоли

app.js

import * as flsFunctions from "./modules/function.js";

flsFunctions.isWebp();

function.js

export function isWebP() {

    function testWebP(callback) {
        let webP = new Image();
        webP.onload = webP.onerror = function () {
            callback(webP.height == 2);
        };
        webP.src = "data:image/webp;base64,UklGRjoAAABXRUJQVlA4IC4AAACyAgCdASoCAAIALmk0mk0iIiIiIgBoSygABc6WWgAA/veff/0PP8bA//LwYAAA";
    }
    
    testWebP(function (support) {
        let className = support === true ? 'webp' : 'no-webp';
        document.documentElement.classList.add(className);
    });
}

Error :

ERROR in ./src/js/app.js 3:0-19
export 'isWebp' (imported as 'flsFunctions') was not found in './modules/function.js' (possible exports: isWebP)