PWA push server knows where to send after device restarts

I am currently studying PWA and bumped into a question about push API. I found this question and answer and they are clear but I still have my question unanswered.

When push server sends browser service worker notifications, that's because the browser subscribed to the notification server with unique endpoint with a token to identify that is the particular browser to send notification to.

However, endpoint involves IP address or domain, if I subscribed to notification at home and then go to public WiFi, I still receive notification, how does the notification server know where to push to though because what notification server stores is my previous endpoint with home WiFi IP.

Thanks in advanced.