app.js

      {
                !isAuthenticated && (
                      <>
                    <div className="wp-block-button">
                          <button type="button" onClick={this.handleRegister} className="wp-block-button-__link">..</button>
                    </div>
                    <div className="wp-block-button wp-block-button--disabled">
                          <button type="button" className="wp-block-button__link">...*</button>
                    </div>
                      </>
                      )
    }