This is an exemple widget for Garmin IQ WebRequest with JSON data. It is based on the following GarminWebRequestTest project: https://github.com/abs0/GarminWebRequestTest
I have added some very simple code to extract the data from the JSON and display the values to the watch widget. Please see the comments in the code. It is tested on a Vivoactive 4.
Visit Garmin Connect IQ Developer site for more information and developer support: https://developer.garmin.com/connect-iq/overview/
This is what a more advanced implemetation could look like. The screenshot is from my home weather station data published as JSON data and imported to Garmin Widget:
