import StudioEditor from '@grapesjs/studio-sdk/react';
import '@grapesjs/studio-sdk/style';

// ...
<StudioEditor
  options={{
    // ...
    project: {
      type: 'email',
      default: {
          pages: [
            {
              component: '<mjml><mj-body><mj-section><mj-column><mj-text>My email</mj-text></mj-column></mj-section></mj-body></mjml>'
            },
          ]
      },
    },
    i18n: {
      locales: {
        en: {
          actions: {
            importCode: {
              content: 'Paste here your MJML code and click Import'
            }
          }
        }
      }
    }
  }}
/>