Yes now I use Wireshark and see the HTTPs encrypted traffic between my IoT device and the IoT cloud.
However, the reason I want to use Fiddler is that if I can install the Fiddler certificate to my IoT device, I can launch MITM attacks and all these HTTPs communicaitons can be decrypted.
In Wireshark, I don't know if it supports such MITM attacks.
reconfigure the Fiddler port(s) ?
or set up a port bouncer.
Yes - but it's complicated.
In short that you need is called "transparent proxy". But Fiddler doesn't support it.
Here is how you can do it with MiTM proxy:
Wireshark also support TLS dissection:
But as i said in beginning it's complicated.
Reconfigure Fiddler's port to what?
It seems like mitmproxy is a better option than Fiddler, since it supports transparent proxy and it offers a certificate...
You should first use wireshark to confirm, that your IoT device really uses https. There is a much better chance, that it uses mqtts (mqtt plus TLS). Which is a completely different protocol compared to https. I very doubt, that fiddler can handle it.
Thanks. I have checked that it uses HTTPs.