partition-jlg-theme/resources/scripts/custom-editor-script.js

(function($) {
    // Access the page content
    var pageContent = pageContentData.content;

    // Now you can use the 'pageContent' variable in your JavaScript code
    console.log(pageContent);

    setTimeout(() => {
        let editorWriting = document.querySelector('.edit-post-visual-editor');
        let writingSpace = document.querySelector('.block-editor-writing-flow');
        writingSpace.style.padding = "0";
        console.log(editorWriting);
        let tutorialWrapper = document.createElement('div');
        tutorialWrapper.style.width = "100%";
        tutorialWrapper.style.backgroundColor = "#384756";
        tutorialWrapper.style.padding = "20px";
        tutorialWrapper.innerHTML = pageContent;
        editorWriting.appendChild(tutorialWrapper);
    }, 2000);

})(jQuery);