How do you add a Linux user on the host system to files on a docker volume?

I have this .yaml file:

version: '3.9'

services:
  postgresql-postgis:
    build: ./postgresql-postgis
    image: image-postgresql-postgis-eb:v.1.0
    container_name: container-postgresql-postgis-eb
    ports:
      - 5432:5432
    volumes:
      - type: bind
        source: ./volumes/data-postgresql
        target: /var/lib/postgresql
    environment:
      POSTGRES_USER: "postgres"
      POSTGRES_PASSWORD: "******************"
      POSTGRES_DB: "tabellapostgres"
      ALLOW_IP_RANGE: "0.0.0.0/0"
    restart: always
    networks:
      - eb

  pgadmin:
    ...

  java:
    ...

networks:
  eb

I have this Dockerfile:

FROM kartoza/postgis:14-3.2--v2022.05.09
EXPOSE 5432

I would like to perform a database backup without using pdAdmin but by copying the data-postgresql folder locally on my computer. If I try to copy the data-postgresql folder on my pc I get this error:

Error: Directory/home/ubuntu/ServerDockerJava01/volumes/data-postgresql/14/main: permission denied Error: Failed to retrieve directory listing