Router catch all CloudFlare API and our site

Hello Team,

This is my first post here :).Nice to meet you all :).

I am very new with Traefik. I am working like DevOps engineer, and I have one task for staging. We have one swarm cluster, one manager and 4 workers with nginx and traefik. Stage and Prod are placed in the same architecture. We have small social network and our Devs implement new feature with CloudFlare API. Users can add their domains and when someone open their domain, CloudFlare will send information about our server, and Traefik will open their personal page. Please tell me how to implement this solution, at least give me some hints, as I don't have experience, it is very hard to start to look solution.