<div class="loyalty-form__checkboxes">
                    <div class="loyalty-form__checkbox">
                        <img class="loyalty-form__checkbox-img" src="<?php echo get_template_directory_uri() ?>/assets/images/static/checkcake.png" alt="">
                        <input type="checkbox" class="loyalty-form__checkbox-style" name="cake" id="cakecheck" onkeyup="checkParams()">
                        <label class="loyalty-form__checkbox-text" for="cakecheck">Хочу скидку на тортики <span
                                class="loyalty-form__pink">*</span></label>
                    </div>

                    <div class="loyalty-form__checkbox">
                        <img class="loyalty-form__checkbox-img" src="<?php echo get_template_directory_uri() ?>/assets/images/static/checkdrink.png" alt="">
                        <input type="checkbox" class="loyalty-form__checkbox-style" name="drink" id="drinkcheck" onkeyup="checkParams()">
                        <label class="loyalty-form__checkbox-text" for="drinkcheck">Очень люблю кофе, хочу скидку
                            <span class="loyalty-form__pink">*</span></label>
                    </div>
                </div>


<form method="post" action="" id="forma" name="">
        <input id="name" onkeyup="checkParams()" class="form-element" type="text" placeholder="Введите имя"
            autocomplete="off" /><br>
        <input id="email" onkeyup="checkParams()" class="form-element" type="email" placeholder="Введите e-mail"
            autocomplete="off" /><br />
        <input id="phone" onkeyup="checkParams()" class="form-element" type="tel" placeholder="Введите телефон"
            autocomplete="off" /><br />
        <input type="button" id="submit" value="Отправить" disabled>
  
   <input type="checkbox" required="" name="check"
                        id="personaldata">
                    <label for="personaldata">Согласен(а) на обработку моих
                        персональных
                        данных</label>

function checkParams() {
            var name = $('#name').val();
            var email = $('#email').val();
            var phone = $('#phone').val();

            if (name.length != 0 && email.length != 0 && phone.length != 0){                            $('#submit').removeAttr('disabled');
            } else {
                $('#submit').attr('disabled', 'disabled');
            }
        }

$('#personaldata').change(function () {
    $('#submit').prop("disabled", !this.checked);
}).change()