WhatsApp Web does not work without having the native app installed on your phone. It’s not a standalone Web app like other messenger apps, so you cannot simply use the Web version and uninstall the native app.
WhatsApp developers intentionally check your phone size and refuse to let you use WhatsApp on your mobile phone.
Even if you turn on Desktop Mode in Hermit, WhatsApp still refuses to work on a mobile phone.
This is not a limitation of Hermit, but WhatsApp going out of their way to block you from using it on a mobile phone.
If you don’t like this (we don’t either!), please complain to WhatsApp, because they are the only ones who can address this problem.
Writing a negative review for Hermit won’t fix this, and there is nothing we can do about it, unfortunately!