docker image cannot find file or path

So I am trying to integrate node into this docker-compose file:

services:
  web:
    image: nginx:1.14.2-alpine
    volumes:
      - ./public_html:/public_html
      - ./conf.d:/etc/nginx/conf.d/
      - ./dhparam:/etc/nginx/dhparam
      - ./certbot/conf/:/etc/nginx/ssl/
      - ./certbot/data:/usr/share/nginx/html/letsencrypt
    ports:
      - 80:80
      - 443:443
      - 4000:4000

because in this public_html folder there is a server.ts file which I need to run. Optimal would be a solution where I can run in the docker-compose file a command: