Multiple domains and resolver

Traefik Traefik v2
1

Hello,
I am new on traefik and i want use this for manage my server (with multiple domains).

My question is how i can manager different domains (with different resolver).
Currently i am locked at how i can define different env keys.

For my main domain (on traefik docker-compose) i have :

env_file: .env
environment:
  - OVH_ENDPOINT
  - OVH_APPLICATION_KEY
  - OVH_APPLICATION_SECRET
  - OVH_CONSUMER_KEY
[...]
labels:
[...]
- traefik.http.routers.traefik.tls.certresolver=ovh
- traefik.http.routers.traefik.tls.domains[0].main=domain.com
- traefik.http.routers.traefik.tls.domains[0].sans=*.domain.com
[...]

If it possible i want use same easy settings for different domains (all domains are on ovh but in different accounts).

Another question : Its possible to make an fallback server if the host is not registered ?

Thanks for your help.