Ajax sending data for wordpress

script.js

// document ready function
let ready = callback => {
    if (document.readyState !== "loading") {
        callback();
    } else {
        document.addEventListener("DOMContentLoaded", callback);
    }
}

async function postData(url = '', data = {}) {
    const response = await fetch(url, {
        method: 'POST', // *GET, POST, PUT, DELETE, etc.
        mode: 'cors', // no-cors, *cors, same-origin
        cache: 'no-cache', // *default, no-cache, reload, force-cache, only-if-cached
        credentials: 'same-origin', // include, *same-origin, omit
        headers: {
            'Content-Type': 'application/x-www-form-urlencoded',
        },
        body: data
    });

    if (response.status >= 400) {
        throw new Error('There was some error on the server');
    }

    return await response.json(); // parses JSON response into native JavaScript objects
}

ready(() => {
    // get form
    let form = document.getElementById('form');
    
    form.addEventListener('submit', function (e) {
        e.preventDefault();

        let $this = this,
            formData = new FormData($this);
      
        // adding action name
        formData.append('action', 'send_ajax');
      
        // adding nonce
        formData.append('nonce', myajax.nonce);

        const data = new URLSearchParams(formData);

        postData(myajax.url, data)
            .then(resp => {
                if (resp.success) {
                    let {name, email, text} = resp.data;
                    alert(`
                    Your name: ${name}
                    Your email: ${email}
                    Your text: ${text}
                    `);
                    $this.reset();
                }
            })
            .catch(error => {
                console.error(error);
        });
    });
});