Container status is unhealthy running alongside Nginx Proxy Manager

[rubylaser]

I have been using Nginx Proxy Manager for a months and it's been working great (along with about 20 other Docker containers). I wanted to setup step-ca to provide ssl certs to my internal hosts. I can't figure this out, so I'm sure that must be using this container incorrectly, because it shows up as Unhealthy status. It's trying to use port 443 which conflicts with NPM. I have this all setup in docker compose like this.

    nginx-proxy-manager:
        hostname: nginx-proxy-manager
        container_name: nginx-proxy-manager
        ports:
            # Public HTTP Port:
            - '80:80'
            # Public HTTPS Port:
            - '443:443'
            # Admin Web Port:
            - '1881:81'
        environment:
            # These are the settings to access your db
            DB_MYSQL_HOST: "db"
            DB_MYSQL_PORT: 3306
            DB_MYSQL_USER: "npm"
            DB_MYSQL_PASSWORD: "npm"
            DB_MYSQL_NAME: "npm"
            DISABLE_IPV6: 'true'
        volumes:
            - /docker/containers/nginx-proxy-manager/data:/data
            - /docker/containers/nginx-proxy-manager/letsencrypt:/etc/letsencrypt
        depends_on:
            - db
        restart: unless-stopped
        image: 'jc21/nginx-proxy-manager:latest'

    db:
        hostname: db
        container_name: db
        environment:
            MYSQL_ROOT_PASSWORD: 'npm'
            MYSQL_DATABASE: 'npm'
            MYSQL_USER: 'npm'
            MYSQL_PASSWORD: 'npm'
        volumes:
            - /docker/containers/nginx-proxy-manager/data/mysql:/var/lib/mysql
        image: 'jc21/mariadb-aria:latest'
        restart: unless-stopped
    stepca:
        container_name: step-ca
        networks:
          default:
            aliases:
              - ca.lab
        image: nginxproxymanager/testca

I have created an internal DNS entry that resolves properly to ca.lab. Here's what the log shows. I don't see

docker logs -f step-ca
badger 2022/03/18 00:10:44 INFO: All 0 tables opened in 0s
2022/03/18 00:10:44 Serving HTTPS on :443 ...

I'm also unclear, even if the port conflict is resolved, exactly how to use this alongside NPM. There is no /home/step directory being created on the host either, although I can see them in the running container.

root@frontend:~# docker exec -it step-ca /bin/bash
bash-5.1$ cd certs/
bash-5.1$ ls
intermediate_ca.crt  root_ca.crt

I guess I'm not exactly sure how I'm supposed to use this to generate certs for my other internal Docker containers. Any help is greatly appreciated. Thanks!