Add DOMAIN_NAME to caddy

docker-compose.yml

@@ -70,6 +70,8 @@ services:
       - '80:80'
       - '443:443'
       - '443:443/udp'
+    environment:
+      DOMAIN_NAME: ${DOMAIN_NAME}
     volumes:
       - ./data/caddy:/data
       - ./config:/etc/caddy