As you’ve asked the question showing your app in Adalo, in my reply I was implicitly meaning Adalo apps. For Adalo apps sharing in PWAs is not supported. Probably I didn’t formulate my answer precisely enough.
For PWAs in general sharing could be supported on some platforms and in some browsers, you’re right. As I understand this is done via WebShare API. I can imagine that some custom component could be built for this - or we should wait till Adalo implements it