How to scale Heroku Django Celery app with Docker - django

Question

I'm trying to deploy my Django app to Heroku and i have several doubts about dynos, workers and deploy configuration.
In my heroku.yml file I have 2 types of processes, one for the web and the other for celery, I would like them to both have only 1 dyno but with several workers and to be scalable if necessary.
heroky.yml:
build:
docker:
web: Dockerfile-django
celery: Dockerfile-django
run:
web: gunicorn project.wsgi --log-file -
celery: celery -A project worker -B --loglevel=INFO
docker-compose.yml:
version: '3.7'
services:
web:
container_name: dilains_django_ctnr
build:
context: .
dockerfile: Dockerfile-django
restart: always
env_file: ./project/project/.env
command: python manage.py check
command: python manage.py runserver 0.0.0.0:8000
volumes:
- ./project:/dilains
depends_on:
- postgres
- redis
ports:
- 8000:8000
networks:
- dilains-ntwk
redis:
container_name: dilains_redis_ctnr
build:
context: .
dockerfile: Dockerfile-redis
volumes:
- ./redis-data:/data
ports:
- 3679:3679
networks:
- dilains-ntwk
celery:
container_name: dilains_celery_ctnr
build:
context: .
dockerfile: Dockerfile-django
restart: always
env_file: ./project/project/.env
command: celery -A project worker -B --loglevel=INFO
volumes:
- ./project:/dilains
depends_on:
- redis
- web
- postgres
networks:
- dilains-ntwk
networks:
dilains-ntwk:
driver: bridge
Dockerfile-django:
FROM python:3.7-alpine
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
RUN apk update && apk add --no-cache bash postgresql postgresql-dev gcc python3-dev musl-dev jpeg-dev zlib-dev libjpeg
RUN mkdir /dilains
COPY ./project /dilains/
COPY ./requirements.txt /dilains/
WORKDIR /dilains
RUN pip install -r requirements.txt
EXPOSE 8000
I tried scale with this commands to scale each process type with 4 workers:
$ heroku ps -a app_name
=== celery (Standard-1X): /bin/sh -c celery\ -A\ project\ worker\ -B\ --loglevel\=INFO (1)
celery.1: up 2020/10/23 08:05:31 +0200 (~ 41m ago)
=== web (Standard-1X): /bin/sh -c gunicorn\ project.wsgi\ --log-file\ - (1)
web.1: up 2020/10/23 08:05:40 +0200 (~ 41m ago)
$ heroku ps:scale web=1 worker=4 -a app_name
$ heroku ps:scale celery=1 worker=4 -a app_name
I'm paying Stardar-1X and tells: number of process type - unlimited and horizontally scaling - yes
Anybody could help please ?