After reading the Apple documentation on extensions, it's not clear how Action Extensions get presented to users. The docs mention the Bing translate use case where actions are presented after users tap the Share button. But what if an app, say a chat app, doesn't have a share button? Another example is if the calling app (not the containing app of the extension) presents an option to invoke an Action Extension.
Are these the only two options? In other words, if an app lacks a Share button and doesn't integrate your extension, there's no way to present an Action Extension?