As I've said, this extension is not really helpful if you're distributing your app to a wide audience since it does not work on MIUI.
Why do you need to read WhatsApp notifications? Most of the time, neither WhatsApp nor your users want this, and Google Play will most likely reject your app. You are also violating WhatsApp's ToS by doing so.
Harm To WhatsApp Or Our Users . You must not (or assist others to) directly, indirectly, through automated or other means, access, use, copy, adapt, modify, prepare derivative works based upon, distribute, license, sublicense, transfer, display, perform, or otherwise exploit our Services in impermissible or unauthorized manners, or in ways that burden, impair, or harm us, our Services, systems, our users, or others, including that you must not directly or through automated means:
(f) collect information of or about our users in any impermissible or unauthorized manner; [...]
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