Cast Desktop Using Specific Monitor

I have been trying to cast my desktop to my Chromecast. However, I find that Brave always casts my second monitor when the latter is plugged in, with no option to change which monitor will be cast. On Chrome, a dialogue always appears asking me which screen I would like to cast with an option to enable casting sound as well; on Brave, no such option appears (although, to be clear, I can successfully cast the monitor that I don’t want to use). Is there some way to force this dialogue to appear? Right now, I’m just using Chrome whenever I want to cast my desktop, but I would prefer to be able to do this from inside Brave.

I have enabled Media Router, and casting tabs works fine; it’s just that I cannot select which monitor to use when casting my desktop.