Restart a docker container periodically with docker-compose

docker-compose.yml

version: '3'
services:
  app:
    image: nginx:alpine
    ports: ["80:80"]
    restart: unless-stopped

  restarter:
    image: docker:cli
    volumes: ["/var/run/docker.sock:/var/run/docker.sock"]
    command: ["/bin/sh", "-c", "while true; do sleep 86400; docker restart app_app_1; done"]
    restart: unless-stopped

How could I this be used to just restart a portainer container after a system reboot - possibly with a 20 sec delay after the reboot has happened

I have added the proposed lines and edited "app_app_1".
But I get this error:
No log line matching the '' filter

@BulldozerPete it's not an error, there are just no logs for the container.