It's a Firefox thing. The context menu in pwa mode is different from the normal one. This is most likely a bug.
A workaround I sometimes use, is to go to the notification drawer, click the silent pwa notification to copy the URL of the current page, share the copied URL with firefox and finally use the normal context menu.
This is my ringtone: https://m.youtube.com/watch?v=Ljqe4Nj7nBA&pp=ygUKbG9zdCB3b29kcw%3D%3D
And this is my notification sound: https://github.com/mozilla-b2g/gaia/blob/master/shared/resources/media/notifications/notifier_dropplet.opus
Let's turn github into Instagram. Every snippet of code has to be attached to a picture or video...
It's super easy. Having a goal like this is the perfect opportunity to learn how to use git, make PRs and what the difference between TypeScript and JavaScript is.
No there is no way to customize the menu. I found an old bug that mentions adding a share option to the context menu. It is probably worth it to either kick this old bug, mentioning what is still missing, or to create a new bug describing the current issue.