Hi, I am new to Shopify App development, but I have to build a fairly complex app on top of NodeJS and ReactJS. I got stuck with receiving webhook notifications from an external server. I have developed a POST API endpoint in my app to work as a webhook receiver. But the problem is that I need help accessing the API's endpoint (built in the app) from outside the Shopify store.
Great to hear you're working on a Shopify app project! Where is the app currently hosted? If you want to be able to make API calls you should ensure that your app's API endpoint is hosted on a publicly accessible server. When you make a post request to https://app_url/api/notification_reciever what are you seeing?