Clicks on buttons don't work on pn.card

Panel
1 
import panel as pn
pn.extension()
url = "https://discourse.holoviz.org/t/is-there-a-way-to-click-button-and-open-a-new-link-in-a-new-tab/1560/4"
link_button = pn.widgets.Button(name="some link", button_type="primary")
link_button.js_on_click(code="window.open('{url}')".format(url=url))
pn.Card(header=link_button)

If click on button, the link doesn’t open