Database are deleting after every deployment to DigitalOcean App Platform - Django

I did my first deployment to DigitalOcean using App Platform, but I have a problem with Database of Django project

Every time i implement some new code or some changes. PostgreSQL database removes all registered data, admin users, posts, … Why is this problem happening? I appreciate any information. I did the deployment according to:

https://docs.digitalocean.com/products/app-platform/

I appreciate your help, thanks

My DB settings:

if not DEBUG:
    # Postgresql config
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': os.environ.get('DB_NAME'),
            'USER': os.environ.get('DB_USER'),
            'PASSWORD': os.environ.get('DB_USER_PASSWORD'),
            'HOST': os.environ.get('DB_HOST'),
            'PORT': os.environ.get('DB_PORT'),
            'SSLMODE': os.environ.get('DB_SSLMODE'),
        }
    }