Fetch API giving 403 error in Codeigniter 3

 products.push({'<?php echo $this->security->get_csrf_token_name(); ?>':'<?php echo $this->security->get_csrf_hash(); ?>'});
    fetch(url + 'createProducts' ,{
        method: 'POST',
        credentials: 'same-origin',
        mode: 'same-origin',
        headers: {
        'Accept':       'application/json',
        'Content-Type': 'application/json',

        },
        body: JSON.stringify(products)
    }).then(()=>{alert('done'); console.log(response.json());})
        .catch(()=>{alert('error AJAX')});

in products, I have an array of products for my project
ad I am pushing my csrf token too.

But still getting 403 error, please help me resolve this.

Thank You