If you run in Docker network host mode, you only need proxyProtocol when you have another node/container like a load balancer in front of Traefik.
Alternatively to full host mode you can only expose the required ports in host mode.
docker-compose.yml:
version: '3.9'
services:
traefik:
image: traefik:v2.9
ports:
- target: 80
published: 80
protocol: tcp
mode: host
- target: 443
published: 443
protocol: tcp
mode: host
…