Edit JSON - Azure portal
1. Sign in to the Azure portal.
2. From the left menu, choose All services. In the search box, find "logic apps", and then from the results, select your logic app.
3. On your logic app's menu, under Development Tools, select Logic App Code View.
4. The Code View editor opens and shows your logic app definition in JSON format.
Reference:
https://docs.microsoft.com/en-us/azure/logic-apps/logic-apps-enterprise-integration-overview
https://docs.microsoft.com/en-us/azure/logic-apps/logic-apps-author-definitions