How to capture requests between two apps running locally?

My question:
Is there a way to capture requests between 2 apps running locally?

Details (like screenshots):
I’m on windows, running my applications in IntelliJ

I’ve already tried:
I’ve tried using the built in windows proxy settings to route to postman proxy, but it basically shut down all traffic from my machine. Not sure if its my work’s VPN causing issues, or if this is just not the proper way to do it.

Are they browser apps or port 80\443, or desktop apps?

If you want all traffic, then Wireshark might be a better option.

VPN’s can cause problems.

desktop apps running on various ports on my localhost.

@Kristian

Wireshark will show all traffic. And I do mean all traffic. Therefore prepare what you want to check first. Turn on the wireshark proxy, do what you need to test and then turn it off sharpish, otherwise the logs can get very large, very quickly.

It’s useful to have a networks person at hand who can help you interpret the logs.