Display different in browser and device when pull data via $http

Hello everyone,
I was working on $http to get json from my api(start with “https://…” url). When I test on web browser (ionic serve), I can see my api json data. However, if I emulate on device(ionic run ios) it won’t show anything. Does anyone know why? Or is it something wrong or I miss something in my code? I have searched a lot but with no luck…If someone can give me advice.
Thank you so much!