example.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script src="https://cdn.jsdelivr.net/npm/@editorjs/editorjs@latest"></script>
<script src="src/uploader.js"></script>
<script src="src/index.js"></script>
<link href="src/index.css" rel="stylesheet"/>

<div id="editorjs"></div>

<button id="save-button">Save</button>
<pre id="output"></pre>

<script>
    const editor = new EditorJS({
        autofocus: true,
        tools: {
            checkmarks: {
                class: HistoryList,
                config: {
                    field: 'media',
                    additionalRequestData: {
                        collectionName: 'personality_preview',
                    },
                    additionalRequestHeaders: {
                        'X-CSRF-TOKEN': 'atMjlQTIPksjkBHRdVIU4FuYyVIK0wPfgMkTeORw'
                    },
                    endpoint: 'http://speka.loc.com/editor/api/posts/527/media',
                    namePlaceholder: 'Заголовок',
                    nameDescriptionPlaceholder: 'Підпис до заголовка',
                    descriptionPlaceholder: 'Опис',
                    linkPlaceholder: 'Посилання',
                    labelPlaceholder: 'Мітка'
                },
            }
        }
    });

    const saveButton = document.getElementById('save-button');
    const output = document.getElementById('output');

    saveButton.addEventListener('click', () => {
        editor.save().then( savedData => {
            output.innerHTML = JSON.stringify(savedData, null, 4);
        })
    })
</script>
</body>
</html>