Not sure if this is a bug or a feature that's just not available everywhere, but I'd like to easily go from viewing the Booking.com website in Opera to opening the Booking app that's on my phone. When I click links in emails, they take me to the webpage in my default browser, Opera. I'd then like to go directly from that webpage to open the Booking app.

The Always open page in External App option is present when I click on site settings for the Booking URL when it's open in Opera, but it is greyed out and I can change the setting. I assume that if I can change the setting, then there'd be a menu option or button somewhere to go directly from that webpage to the app.

Note, page sharing options in Opera don't allow me to share the page to Booking app.

Thanks for any suggestions.