Themes don't look like in example monaco-react

Question

I selected theme from this list https://monaco-react.surenatoyan.com/ and download JSON https://github.com/brijeshb42/monaco-themes/blob/master/themes/Tomorrow.json

const TOMORROW_MONACO_THEME = require('./Tomorrow.json');


<Editor height={'80vh'}
        defaultLanguage="JSON"
        defaultValue={defaultValue}
        onChange={handleEditorChange}
        theme={'myCustomTheme'}
        onMount={handleEditorOnMount}
/>

function handleEditorOnMount(editor, monaco) {
  // Define the new theme
  monaco.editor.defineTheme('myCustomTheme', TOMORROW_MONACO_THEME);
  // Apply the new theme
  monaco.editor.setTheme('myCustomTheme');
};

The theme is applied but it isn't look like in example.