How do I change the interface on Tshark?

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Hello, everyone!

I'm trying to change the interface that's being currently used by Tshark. The interface in used is Local Area Connection 2, but I'm using my wifi which is the one I'd like to use since I'm not connected through a wire. I can't manage the change that. It doesn't allow me to key any commands. And It is my understanding that first I need to select the wifi when Wireshark starts, which I've done.

I'm going nuts, if you can, please, give me a hand. :D

As a quick remark I'm using Windows. I cannot use Linux at the moment because I don't know how to use it, I don't know if that is a problem...