Deploying a fastapi and celery app with docker

I built an app in python using the fastapi and celery libraries and now I want to deploy it using docker on render or any other free hosting platform, both of them have to run as different services but my fastapi endpoint calls the celery task so I really cant use separate codebases for them, usually on my computer I would just run the command to start the celery app and the command to start the fastapi server
What is the best way to deploy this application?