Why I have pre output in my ajax request?

I’ve been working for this for 5 hours. No matter what I do, there is <pre></pre> in my output. I’ve tried at least 10 different javascript and php combinations for ajax. But none of them worked. pre haunts me.

This is my PHP code:

function ewfb_license_control_ajax(){
    wp_send_json_success();
    wp_die();
}
add_action( 'wp_ajax_ewfb_license_control_ajax', 'ewfb_license_control_ajax' );

This is my javascript code:

jQuery.post(ajaxurl, data, function (response) {
        console.log(typeof response);
        console.log(response);
 }, 'html');

And this is my output:
<pre></pre>{"success":true}