import Warning from '@editorjs/warning';

var editor = CodexEditor({
  ...
  
  tools: {
    ...
    warning: Warning,
  },
  
  ...
});

var editor = CodexEditor({
  ...
  
  tools: {
    ...
    warning: {
      class: Warning,
      inlineToolbar: true,
      shortcut: 'CMD+SHIFT+W',
      config: {
        titlePlaceholder: 'Title',
        messagePlaceholder: 'Message',
      },
    },
  },
  
  ...
});