1. install podman latest version:

2. below steps add in a shell script and execute:

sudo sysctl net.ipv4.ip_unprivileged_port_start=80

systemctl --user enable podman.socket
systemctl --user start podman.socket
systemctl --user status podman.socket

podman rm -f pmm-server
podman rm -f watchtower

podman network create pmm-network

podman pull docker.io/perconalab/pmm-server:3.0.0-rc
podman pull docker.io/perconalab/watchtower:3.0.0-rc

mkdir -p ~/.config/systemd/user/
cat > ~/.config/systemd/user/watchtower.service <<EOF
[Unit]
Description=watchtower
Wants=network-online.target
After=network-online.target
After=nss-user-lookup.target nss-lookup.target
After=time-sync.target

[Service]
Restart=on-failure
RestartSec=20

ExecStart=/bin/bash -l -c '/usr/bin/podman run --rm --replace=true --name watchtower \
--security-opt label=disable \
-v $XDG_RUNTIME_DIR/podman/podman.sock:/var/run/docker.sock \
-e WATCHTOWER_HTTP_API_UPDATE=1 \
-e WATCHTOWER_HTTP_API_TOKEN=123 \
-e WATCHTOWER_NO_RESTART=1 \
-e WATCHTOWER_DEBUG=1 \
--net pmm-network \
--cap-add=net_admin,net_raw \
docker.io/perconalab/watchtower:3.0.0-rc >/tmp/options12.debug'

ExecStop=/usr/bin/podman stop -t 10 %N

[Install]
WantedBy=default.target
EOF

systemctl --user enable --now watchtower

attempt=0
while [ $attempt -le 10 ]; do
attempt=$(( $attempt + 1 ))
echo "Waiting for watchtower to be up (attempt: $attempt)..."
result=$(systemctl --user status watchtower)
echo "$result"
if grep "he HTTP API is enabled at :8080." <<< $result ; then
echo "watchtower is ready!"
break
fi
sleep 10
done;

mkdir -p /home/pmm/
cat > /home/pmm/pmm-server.env <<EOF
PMM_WATCHTOWER_HOST=http://watchtower:8080
PMM_WATCHTOWER_TOKEN=123
PMM_DEV_UPDATE_DOCKER_IMAGE=docker.io/perconalab/pmm-server:3-dev-latest
PMM_IMAGE=docker.io/perconalab/pmm-server:3.0.0-rc
EOF

chmod 777 /home/pmm/pmm-server.env
rm -f ~/.config/systemd/user/pmm-server.service

mkdir -p ~/.config/systemd/user/
echo "
[Unit]
Description=pmm-server
Wants=network-online.target
After=network-online.target
After=nss-user-lookup.target nss-lookup.target
After=time-sync.target

[Service]
EnvironmentFile=/home/pmm/pmm-server.env

Restart=on-failure
RestartSec=20

ExecStart=/usr/bin/podman run --volume /home/pmm/:/home/pmm/update/ \
--rm --replace=true \
--name pmm-server \
--env-file=/home/pmm/pmm-server.env \
--net pmm-network \
--cap-add=net_admin,net_raw \
--userns=keep-id:uid=1000,gid=1000 \
-p 80:8080/tcp -p 443:8443/tcp \
--ulimit=host \${PMM_IMAGE}

ExecStop=/usr/bin/podman stop -t 10 %N

[Install]
WantedBy=default.target

" >> ~/.config/systemd/user/pmm-server.service

systemctl --user enable --now pmm-server

export CONTAINER_NAME="pmm-server"
export LOGS="pmm-managed entered RUNNING state"
attempt=0
while [ $attempt -le 20 ]; do
attempt=$(( $attempt + 1 ))
echo "Waiting for ${CONTAINER_NAME} to be up (attempt: $attempt)..."
result=$(systemctl --user status ${CONTAINER_NAME})
echo "$result"
if grep "${LOGS}" <<< $result ; then
echo "${CONTAINER_NAME} is ready!"
break
fi
sleep 5
done;

3. Go to ui and hit upgrade notice the internal error

https://github.com/percona/pmm/pull/3520