I have created a new tag in the Launch and build it properly for dev environment which shows a green color. However, the tag was not visible on the network panel whereas it was visible on the console panel showing "tag fired".
Please help in viewing the tag on the network panel.
From that, it sounds like you have a 'Set Variables' action in your rule. Do you have a 'Send Beacon' action in your rule as well? I also generally recommend having a 'Clear Variables' action after every time a beacon is sent, but that will depend on how you're designing the beacons you send.
Assuming you're sending a beacon, you have a few options for locating it.
Option 1) The easiest way I've found to locate it in the Network tab would be to filter based on the name of the report suite you're reporting to. Just grab whatever you configured in your Launch Extension config and throw that in the network tab.
Option 2) If you still can't find your beacon, there other good option would be to filter based on your tracking server. Unless you've done explicit setup otherwise, using "omtrdc.net" would be a good filter to try (the root domain of the Analytics RDCs). If you have configured a tracking server, try using that.
You should be able to find a beacon that looks like the second entry in the screencap below. If your beacon is really large (over 2,000 characters), it will look a little different because AA will reformat it as a POST request instead of a GET. You should still find it with the same filter criteria, it will just be tougher to decipher.
Option 3) Lastly - a way to simplify the process would be to use the Adobe Debugger (Docs here: Adobe Debugger) If you're just getting started with an implementation, that will reduce your need to fight with the Network tab just to find an Analytics beacon if that's your goal. That said, in the aforementioned situation where it has turned into a POST request due to the amount of data being transmitted, the Debugger will not show it.