How to rewrite costum Gdpr cookie consent jquery code snippet into pure javascript

Question

I need help with Gdpr cookie consent Jquery code snippet below to rewrite it into pure javascript. Can any one please help me rewrite it into pure javascript? Thanks in advance.

Jquery:

$(document).ready(function () {
    if (document.cookie.indexOf("gdpr_mandatory=") == -1) {
        $('#gdpr_basic').modal({
            backdrop: false
        });
    }
});
$('#gdpr_btn_full_agree').click(function (e) {
    e.preventDefault();
    var date = new Date();
    date = new Date(date.getTime() + 1000 * 60 * 60 * 24 * 365);
    document.cookie = "gdpr_mandatory=1; expires=" + date.toGMTString() + "; path=/";
    document.cookie = "gdpr_functional=1; expires=" + date.toGMTString() + "; path=/";
    document.cookie = "gdpr_ga=1; expires=" + date.toGMTString() + "; path=/";
    document.cookie = "gdpr_fbp=1; expires=" + date.toGMTString() + "; path=/";
    $('#gdpr_basic').modal('hide');
});
$('#gdpr_btn_adjust').click(function (e) {
    e.preventDefault();
    $('#gdpr_basic').modal('hide');
    $('#gdpr_adjust').modal();
});
$('#gdpr_btn_save').click(function (e) {
    e.preventDefault();
    $('#gdpr_adjust_form').submit();
});
$('#gdpr_adjust_form').on('submit', function (e) {
    e.preventDefault();
    $(this).find('input[type="checkbox"]').each(function (e) {
        var fieldName = $(this).attr('name');
        var fieldValue = $(this).is(':checked') ? 1 : 0;
        var date = new Date();
        date = new Date(date.getTime() + 1000 * 60 * 60 * 24 * 365);
        document.cookie = fieldName + "=" + fieldValue + "; expires=" + date.toGMTString() + "; path=/;";
    }) toastr["info"]("Saved");
    $('#gdpr_adjust').modal('hide');
});

I have found online site that converts query to Pure Javascript but it doesn't work properly. This is converted code snippet:

document.querySelector(document).ready(function () {
    if (document.cookie.indexOf("gdpr_mandatory=") == -1) {
        document.querySelector('#gdpr_basic').modal({
            backdrop: false
        });
    }
});
document.querySelector('#gdpr_btn_full_agree').click(function (e) {
    e.preventDefault();
    var date = new Date();
    date = new Date(date.getTime() + 1000 * 60 * 60 * 24 * 365);
    document.cookie = "gdpr_mandatory=1; expires=" + date.toGMTString() + "; path=/";
    document.cookie = "gdpr_functional=1; expires=" + date.toGMTString() + "; path=/";
    document.cookie = "gdpr_ga=1; expires=" + date.toGMTString() + "; path=/";
    document.cookie = "gdpr_fbp=1; expires=" + date.toGMTString() + "; path=/";
    document.querySelector('#gdpr_basic').modal('hide');
});
document.querySelector('#gdpr_btn_adjust').click(function (e) {
    e.preventDefault();
    document.querySelector('#gdpr_basic').modal('hide');
    document.querySelector('#gdpr_adjust').modal();
});
document.querySelector('#gdpr_btn_save').click(function (e) {
    e.preventDefault();
    document.querySelector('#gdpr_adjust_form').submit();
});
document.querySelector('#gdpr_adjust_form').addEventListener('submit', function (e) {
    e.preventDefault();
    document.querySelector(this).querySelector('input[type="checkbox"]').each(function (e) {
        var fieldName = document.querySelector(this).attr('name');
        var fieldValue = document.querySelector(this).is(':checked') ? 1 : 0;
        var date = new Date();
        date = new Date(date.getTime() + 1000 * 60 * 60 * 24 * 365);
        document.cookie = fieldName + "=" + fieldValue + "; expires=" + date.toGMTString() + "; path=/;";
    }) toastr["info"]("Saved");
    document.querySelector('#gdpr_adjust').modal('hide');
});

This is the link to the code snippet that shows converted Pure Javascript file errors: Converted Javascript