Where is my database using Portainer for NC installation?

Hello.

On my old server I had nextcloud with docker and Portainer to build the stack.
In the text below I showing my docker-compose file, it was a copy/paste from some website and I wasn’t aware that the database volume was in a relative path ./db:/var/lib/mysql

How can I recover the database? I can’t find it for any volume

version: '2'
services:
  db:
    image: mariadb:10.5.11
    restart: always
    command: --transaction-isolation=READ-COMMITTED --binlog-format=ROW
    volumes:
      - ./db:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD="foo"
      - MYSQL_PASSWORD="bar"
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextcloud

  nextcloud:
    image: iamklaus/nextcloud
    restart: always
    container_name: nextcloud_nextcloud_1
    hostname: mynextcloud.es
    ports:
      - "8001:80"
      - "8443:443"
    links:
      - db
    volumes:
      - /docker/nextcloud/config:/var/www/html/config
      - /docker/nextcloud/data:/var/www/html/data 
      - /docker/nextcloud/custom_apps:/var/www/html/custom_apps
      - /docker/nextcloud/themes:/var/www/html/themes
    environment:
      - MYSQL_PASSWORD="bar"
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextcloud
      - MYSQL_HOST=db
      - PHP_MEMORY_LIMIT=8G

volumes:
  nextcloud:
  db:

there must be a folder db where you have your docker-compose.yaml stored…

I’m a linux user from long ago but I can’t find this folder, I don’t understand and as a newbie docker user I thought something was missing.
Creating the docker-compose from portainer, where is locate the docker-compose.yaml?

Thanks for your comment anyway

I only had a quick look at portainer, so can’t help you, sorry. I wasn’t even aware portainer can manage docker-compose files… I was under impression is interacts directly with docker daemon.

I would recommend you to search for docker-compose or consult portainer docs.

quick internet search shows this results:

https://bleepcoder.com/portainer/553647944/where-are-the-stack-compose-files-saved