Docker, the panel can not be installed

I’m trying to deploy Kirby on a server using Docker. It works well in my local Docker environment, but on the Ubuntu server, I get an error saying that the panel cannot be found or installed. Below are my Dockerfile and compose files.

Docker-compose.yml

version: "3"
services: 
  webserver:
    build:
      context: ./kirbyserver
      dockerfile: Dockerfile
    container_name: kirby_server
    environment:
      USERID: '1001'
    # image: docker-starterkit
    # expose:
    #   - "80" 
    ports:
      - "8000:80"
    volumes:
      - ./kirbyserver/backend:/var/www/html:rw 
    env_file:
      - ./kirbyserver/id.env

Dockerfile

# Use latest official Ubuntu image
FROM ubuntu:latest

# Set timezone
ENV TZ=Europe/Berlin

# Set geographic area using above variable
# This is necessary, otherwise building the image doesn't work
RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone

# Remove annoying messages during package installation
ARG DEBIAN_FRONTEND=noninteractive

# Install packages: web server & PHP plus extensions
RUN apt-get update && apt-get install -y \
  apache2 \
  apache2-utils \
  ca-certificates \
  php \
  libapache2-mod-php \
  php-curl \
  php-dom \
  php-gd \
  php-intl \
  php-json \
  php-mbstring \
  php-xml \
  php-zip \
  git && \
  apt-get clean && rm -rf /var/lib/apt/lists/*

# Clone the Kirby starter kit repository into the /app directory
RUN git clone --depth 1 https://github.com/getkirby/starterkit.git /app

# Copy virtual host configuration from current path onto existing 000-default.conf
COPY default.conf /etc/apache2/sites-available/000-default.conf

# Set up necessary directories and permissions
RUN mkdir -p /app/site/accounts /app/site/sessions && \
    chown -R www-data:www-data /app && \
    chmod -R 755 /app

# Remove default content (existing index.html)
RUN rm -rf /var/www/html && ln -s /app /var/www/html

# Activate Apache modules headers & rewrite
RUN a2enmod headers rewrite

# Change web server's user id to match local user, replace with your local user id
RUN usermod --uid 1001 www-data

# Tell container to listen to port 80 at runtime
EXPOSE 80

# Start Apache web server
CMD [ "/usr/sbin/apache2ctl", "-DFOREGROUND" ]


and this is my config.php

return [
    'api' => [
      'basicAuth' => true,
      'allowInsecure' => true, // localhost without https
    ],
    'debug' => true,
    'kql' => [
      'auth' => true
    ],
    'panel' =>[
      'install' => true
    ]
];

Solved