this is my error when i run docker build.

Sending build context to Docker daemon  2.443MB
Step 1/10 : FROM nginx:latest
 ---> ab56bba91343
Step 2/10 : RUN apt-get update
 ---> Running in 67d01cd431e5
Err:1 http://security-cdn.debian.org/debian-security buster/updates InRelease
  Could not connect to security-cdn.debian.org:80 (151.101.36.204), connection timed out
Err:2 http://cdn-fastly.deb.debian.org/debian buster InRelease
  Could not connect to cdn-fastly.deb.debian.org:80 (151.101.36.204), connection timed out
Err:3 http://cdn-fastly.deb.debian.org/debian buster-updates InRelease
  Unable to connect to cdn-fastly.deb.debian.org:http:
Reading package lists...
W: Failed to fetch http://deb.debian.org/debian/dists/buster/InRelease  Could not connect to cdn-fastly.deb.debian.org:80 (151.101.36.204), connection timed out
W: Failed to fetch http://security.debian.org/debian-security/dists/buster/updates/InRelease  Could not connect to security-cdn.debian.org:80 (151.101.36.204), connection timed out
W: Failed to fetch http://deb.debian.org/debian/dists/buster-updates/InRelease  Unable to connect to cdn-fastly.deb.debian.org:http:
W: Some index files failed to download. They have been ignored, or old ones used instead.
Removing intermediate container 67d01cd431e5
 ---> d46ed6512d2b
Step 3/10 : RUN apt-get install -y         curl        git        curl        vim        systemd        systemd-container       net-tools       procps  sudo    iproute2        kmod    iptables
 ---> Running in a04663cbf684
Reading package lists...
Building dependency tree...
Reading state information...
Package systemd is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Unable to locate package curl
E: Unable to locate package git
E: Unable to locate package curl
E: Unable to locate package vim
E: Package 'systemd' has no installation candidate
E: Unable to locate package systemd-container
E: Unable to locate package net-tools
E: Unable to locate package procps
E: Unable to locate package sudo
E: Unable to locate package iproute2
E: Unable to locate package kmod
E: Unable to locate package iptables
The command '/bin/sh -c apt-get install -y         curl        git        curl        vim        systemd        systemd-container       net-tools       procps  sudo    iproute2        kmod    iptables' returned a non-zero code: 100

i really don't know how to solve this. when i do : echo $http_proxy there is nothing. and i don't know what i need to do, i don't know if my probleme is related to this. please help me.