Fixed environment setup

Dockerfile

@@ -1,6 +1,6 @@
 FROM node:alpine
 
-ARG PORT
+ARG PORT="3000"
 ENV PORT=$PORT
 
 COPY . .

src/environment.ts

@@ -7,9 +7,9 @@ dotenv.config();
 dotenv.config({path: '.env.local', override: true});
 
 export const environment = {
-	port: process.env['PORT'] ?? 3000,
+	port: process.env['PORT'] ? +process.env['PORT'] : 3000,
 	production: !process.env.NODE_ENV || ['prod', 'production'].includes(process.env.NODE_ENV.toLowerCase()),
-	tickers: process.env['TICKERS']?.split(',') ?? [],
+	tickers: process.env['TICKERS']?.split(',') || [],
 	token: process.env['TOKEN'],
 	version: packageJson.version
 }