More like a "how-to" question rather than about security, but let's answer

You go to the interfaces window *


> Note: "Even in promiscuous mode you still won’t necessarily see all packets
> on your LAN segment. See the [Wireshark FAQ][1] for more information."


  [1]: https://www.wireshark.org/faq.html#promiscsniff

*<sub>(capture>opt>enable promiscuous mode)</sub>