By default InterSystems IRIS expose your endpoints using http, but can be necessary run https from your dev env and/or get public internet access to your app. You can buy or get a certificate and config a gateway, spending many hours or use a great public service called ngrok. Follow the steps:
1 - Run your app, I will use FHIR template as sample, see:
1.1 download the app: git clone https://github.com/intersystems-community/iris-fhir-template.git