Is there a way to always get the same image from Docker?

I am working on a Docker project and would like to create a reproducible build. In other words, I would like to specify in my .yml file the exact version of each dependency I would like to use. I understand there are tags, but it looks like tags are not necessarily stable (i.e. a tag can be updated, and therefore, by using the tag I’m not guaranteed to get the same version over time).

According to this tags can be updated/replaced/changed:
https://www.howtogeek.com/devops/how-to-add-replace-and-remove-docker-image-tags/

Specifically, I’m working with this codebase:
https://github.com/data61/anonlink-entity-service

And this .yml file:
https://github.com/data61/anonlink-entity-service/blob/develop/tools/docker-compose.yml

And would like to use a stable (unchanging) version of this: data61/anonlink-app

The existing codebase uses this for the version: image: data61/anonlink-app:${TAG:-latest}

Which is also problematic as it is likely to change as well as for a number of other reasons described here: https://medium.com/@mccode/the-misunderstood-docker-tag-latest-af3babfd6375

Full .yml file is shown below

version: '3.4'
services:

  db:
    image: postgres:11.13
    environment:
      - POSTGRES_PASSWORD=rX%QpV7Xgyrz
    volumes:
      - psql:/var/lib/postgresql/data
    #ports:
    #- 5432:5432
    healthcheck:
      test: pg_isready -q -h db -p 5432 -U postgres
      interval: 5s
      timeout: 30s
      retries: 5

  minio:
    image: minio/minio:RELEASE.2021-02-14T04-01-33Z
    command: server /export
    env_file:
      - .env
    volumes:
      - minio:/export
    ports:
      - 9000:9000
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:9000/minio/health/live"]
      interval: 30s
      timeout: 20s
      retries: 3

  redis:
    image: redis:5.0

  # The flask application server
  backend:
    image: data61/anonlink-app:${TAG:-latest}
    env_file:
      - .env
    environment:
      - FLASK_DB_MIN_CONNECTIONS=1
      - FLASK_DB_MAX_CONNECTIONS=10
    depends_on:
      - db
      - db_init
      - redis
      - minio
      - objectstore_init

  # The application server can also setup the database
  db_init:
    image: data61/anonlink-app:${TAG:-latest}
    environment:
      - DEBUG=true
      - DATABASE_PASSWORD=rX%QpV7Xgyrz
      - FLASK_APP=entityservice
    entrypoint: /bin/sh -c "dockerize -wait tcp://db:5432 alembic upgrade head"
    depends_on:
      - db

  # Set up the object store to have another more restricted user
  objectstore_init:
    image: minio/mc:RELEASE.2021-02-14T04-28-06Z
    environment:
      - OBJECT_STORE_SECURE=false
    env_file:
      - .env
    entrypoint: |
      /bin/sh /opt/init-object-store.sh
    volumes:
      - ./init-object-store.sh:/opt/init-object-store.sh:ro
    depends_on:
      - minio

  # A celery worker
  worker:
    image: data61/anonlink-app:${TAG:-latest}
    depends_on:
      - redis
      - db
    command: celery -A entityservice.async_worker worker --loglevel=info -O fair -Q celery,compute,highmemory
    env_file:
      - .env
    environment:
      - CELERY_ACKS_LATE=true
      - REDIS_USE_SENTINEL=false
      - CELERYD_MAX_TASKS_PER_CHILD=2048
      #- CHUNK_SIZE_AIM=300_000_000
      - CELERY_DB_MIN_CONNECTIONS=1
      - CELERY_DB_MAX_CONNECTIONS=3


  nginx:
    image: data61/anonlink-nginx:${TAG:-latest}
    ports:
      - 8851:8851
    depends_on:
      - backend
    environment:
      TARGET_SERVICE: backend
      PUBLIC_PORT: 8851


  # A celery monitor. Useful for debugging.
#  celery_monitor:
#    image: data61/anonlink-app:${TAG:-latest}
#    depends_on:
#      - redis
#      - worker
#    command: celery flower -A entityservice.async_worker
#    ports:
#      - 8888:8888


# Jaeger UI is available at http://localhost:16686
  jaeger:
    image: jaegertracing/all-in-one:latest
    environment:
      COLLECTOR_ZIPKIN_HTTP_PORT: 9411
#    ports:
#      - 5775:5775/udp
#      - 6831:6831/udp
#      - 6832:6832/udp
#      - 5778:5778
#      - 16686:16686
#      - 14268:14268
#      - 9411:9411

volumes:
  psql:
  minio: