Chrome
1. In the address bar, click on this icon
2. Click on 'Notifications' to allow them:
3. Click on Reload
Edge
Click on the lock icon and make sure that notifications are allowed:
Safari on a Mac
On your Mac, choose Apple menu > System Settings, then click Notifications in the sidebar. (You may need to scroll down.)
Go to Application Notifications on the right, click the website, then change the website alert style and other settings.