Hello,
Officially the Portainer is supports only docker, but on some systems we can use only Podman (RHEL systems), with this is hint you can run portainer under podman:
systemctl enable podman
systemctl start podman
#You will need to enable linger for this user in order for the socket to work when the user is not logged in.
loginctl enable-linger $USER
docker run -d -p 8000:8000 -p 9443:9443 --name portainer --restart=always -v /run/podman/podman.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce:latest