App => Load env file for dev or prod

ExpressAPI/src/app.ts

-require('dotenv').config(); // ATTENTION : This line MUST be the first of this file
-require('./shared/helpers/TypeScriptExtensions'); // ATTENTION : This line MUST be the second of this file
+// Read from the .env file
+// ATTENTION : This lines MUST be the first of this file (except for the path import)
+const path = require('node:path');
+
+if ( process.env.NODE_ENV && process.env.NODE_ENV === 'production' ) {
+    require('dotenv').config();
+} else {
+    require('dotenv').config({ path: path.join(__dirname, '../.env.keys') });
+    require('dotenv').config({ DOTENV_KEY: process.env.DOTENV_KEY_DEVELOPMENT });
+}
+
+require('./shared/helpers/TypeScriptExtensions'); // ATTENTION : This line MUST be after the dotenv.config() calls
 
 import WorkerRole     from './process/WorkerRole';
 import ClusterManager from './process/ClusterManager';