Web push notifications problem after updating to Big Sur

Hallo, in our webapp there are implemented web push notifications for Safari users. Now we facing a problem after Update to Big Sur macOs, in Javascript we have a Code snippet to check if a popup should come and ask user if he want notifications but in Big Sur it's not working now.

if ('safari' in window && 'pushNotification' in window.safari) {
// Show popup
}

What should we change in this code to get it working in Safari Big Sur?

Regards,
Przemek Tranda