create post – send attachment

I’m building a web application based on wordpress & wp json plugin.

I created a form for posting a new post with title, content and attachment but the attachment is not passing on

js:

$(document).on("submit", "#add-post #post-upload", function(e) {

    var post_title = $("#add-post input[name='form-post-title']").val();
    var post_content = $("#add-post textarea[name='form-post-content']").val();

    $.ajax({
        url: url + "/create_post?nonce=*******&title=" + post_title + "&content=" + post_content,
        dataType: "json",
        success: function(data){
            console.log(data);
        },
        error: function(data) {
            console.log(data);
        }
    });
});

html code:

<form name="post-upload" id="post-upload" method="post" action="#home" enctype="multipart/form-data">
        <input type="text" name="form-post-title" placeholder="title" />
        <textarea name="form-post-content" placeholder="content"></textarea>
        <input type="file" name="attachment" id="attachment" />
        <input type="submit" value="Submit" />
    </form>

wordpress json api github page (https://github.com/homicidewatch/wordpress-json-api) says it needs to have a input with “attachemnt” as a name for file input. But again, not working for some reason.

https://wordpress.org/plugins/json-api/