There is still no way to install a native Linux application for whatsapp, so I always use whatsapp's webapp with my daily browser (chromium based brave-browser).
Everything works [mostly] fine, except when I need to click on a whatsapp link in a web site, that is supposed to open a conversation with a certain new cell phone number. Here's an example on BOSE's site when you click in the button "message us".
When I click on a button like that one, I get redirected to api.whatsapp.com and then I get a popup prompt on my browser asking:
Open xdg-open?
https://api.whatsapp.com wants to open this application.
If I proceed, nothing happens.
I would expect to have a new whatsapp web tab opened to be able to message the new contact.
I have tried to use xdg-mime but I can't understand how to use it.
You should be able to avoid the xdg popup by blocking JavaScript for api.whatsapp.com through site permissions. Since the webpage has a "continue to chat" link that redirects to web.whatsapp.com, assuming I understood the problem correctly, that link is the solution.