AutoForm doesn't create the input field

I’m having this issue and I can’t figure out why… I created an AutoForm linked to a collection and when I try to create the input field nothing is happening, I only see the name of the Field taken by the collection and nothing else.

This is my Schema Collection:

Posts.attachSchema(new SimpleSchema({
    body: {
        type: String,
        max: 500
    userId: {
        type: String
    username: {
        type: String
    createdAt: {
        type: Date

This is the HTML where I created the AutoForm:

<div class="modal-body">
              {{#autoForm collection="Posts" id="insertPostForm" type="insert"}}
                {{> afQuickField name='body'}}

And this is a screen of what I’m seeing: Screen

I searched a lot for similar issues but nothing, I hope that you all can help me! Thanks.