I couldn't find any info on how to send a web request to a remote rest api with fastlane. The best I could come up with is the "sh" action. My goal is to poll an api point between fastlane actions in order to check if the build is cancelled. I'd be glad if someone could shed some light on this. Here's some pseudocode.
api_query_result = query_api("https://api.mysite.com")
if(api_query_result.status_code == 200)
upload_to_testflight