Subscription permission denied on webapp push

HI, please can someone help? I have a web app where push notifications are in place for Chrome, Firefox, and Edge. Providing the user allows notifications then when they log in for the first time their details are registered to the subscriptions table in the backend. All good so far. When trying to do the same with Safari on Mac I'm faced with this issue: "Safari doesn’t support invisible push notifications. Present push notifications to the user immediately after your service worker receives them. If you don’t, Safari revokes the push notification permission for your site." and the user is no...