apt install docker.io
(add your user in the docker group)

wget https://downloads.raspberrypi.org/raspios_armhf/images/raspios_armhf-2021-03-25/2021-03-04-raspios-buster-armhf.zip
unzip 2021-03-04-raspios-buster-armhf.zip

udisksctl loop-setup --file 2021-03-04-raspios-buster-armhf.img --read-only
>> Mapped file 2021-03-04-raspios-buster-armhf.img as /dev/loop23

sudo tar c -C /media/nats/rootfs . | docker image import - raspios:2021-buster
>> sha256:7745a78147dd3252f00c6a9f6d533101f784dfc46c98327486afc4ba818378a6

This commande will allow docker to run arm system
docker run --rm --privileged docker/binfmt:820fdd95a9972a5308930a2bdfb8573dd4447ad3

docker create -it --name raspbian_test raspios:2021-buster bash

docker create -it --name raspbian_test_graphical -v /tmp/.X11-unix:/tmp/.X11-unix -e DISPLAY=unix$DISPLAY raspios:2021-buster bash

xhost +local:root

docker start -ai raspbian_test_graphical

====== And you have a working docker arm rpi4 =====

Then apply this one

https://pastebin.com/XUsrTXzg