Correct format for load template

Hey,

I'm searching for the right way of loading template, generated by GrapesJS, but nothing is loading.

Can someone please check, maybe format is not ok. https://api.myjson.com/bins/14o5yz

There is no error message, just empty editor.

Data is saved in the database with the following code

$params = file_get_contents('php://input');
$params = json_decode($params, true);

The type of the columns is TEXT.

This is my code

var builder = grapesjs.init({
        container : '#html-wrapper',
        plugins: ['gjs-preset-newsletter', 'gjs-plugin-ckeditor', 'img-link-plugin'],
        clearOnRender: true,
        assetManager: {
            upload: '/index.php?page=mod&mod=' + mod_param + '&action=ajax-upload-images',
            dropzone: true,
        },
        storageManager: {
            id: 'gjs-',
            type: 'remote',
            autoload: true,
            autosave: true,
            storeComponents: true,
            storeStyles: true,
            stepsBeforeSave: 1,
            contentTypeJson: true,
            urlStore: '/index.php?page=mod&mod=' + mod_param + '&action=ajax-save-campaign-template',
            urlLoad: '/index.php?page=mod&mod=' + mod_param + '&action=ajax-load-campaign-template&template_id=' + template.id,
            params: {
                template_id: template.id,
                template_name: template.name
            }
        }
    });