Lab 16.2 Cannot make Lode Balancer work

On step 3, when I restart and check the status of HAProxy Load Balancer, it returns status as "Failed"
What am I doing wrong? Thank you!

Here are the command and the output:

student@ha-proxy:~$ sudo systemctl status haproxy.service
● haproxy.service - HAProxy Load Balancer
Loaded: loaded (/lib/systemd/system/haproxy.service; enabled; vendor preset: enabled)
Active: failed (Result: start-limit-hit) since Mon 2021-04-05 08:01:41 UTC; 10min ago
Docs: man:haproxy(1)
file:/usr/share/doc/haproxy/configuration.txt.gz
Process: 21065 ExecStart=/usr/sbin/haproxy-systemd-wrapper -f ${CONFIG} -p /run/haproxy.pid $EXTRAOPTS (code=exited, status=0/SUCCESS)
Process: 21055 ExecStartPre=/usr/sbin/haproxy -f ${CONFIG} -c -q (code=exited, status=0/SUCCESS)
Main PID: 21065 (code=exited, status=0/SUCCESS)

Apr 05 08:01:41 ha-proxy haproxy-systemd-wrapper[21065]: haproxy-systemd-wrapper: exit, haproxy RC=256
Apr 05 08:01:41 ha-proxy systemd[1]: haproxy.service: Service hold-off time over, scheduling restart.
Apr 05 08:01:41 ha-proxy systemd[1]: Stopped HAProxy Load Balancer.
Apr 05 08:01:41 ha-proxy systemd[1]: haproxy.service: Start request repeated too quickly.
Apr 05 08:01:41 ha-proxy systemd[1]: Failed to start HAProxy Load Balancer.
Apr 05 08:01:41 ha-proxy systemd[1]: haproxy.service: Unit entered failed state.
Apr 05 08:01:41 ha-proxy systemd[1]: haproxy.service: Failed with result 'start-limit-hit'.

Here is my haproxy.cfg file:

global
log /dev/log local0
log /dev/log local1 notice
chroot /var/lib/haproxy
stats socket /run/haproxy/admin.sock mode 660 level admin
stats timeout 30s
user haproxy
group haproxy
daemon

    ca-base /etc/ssl/certs
    crt-base /etc/ssl/private

    ssl-default-bind-ciphers ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+3DES:!aNULL:!MD5:!DSS
    ssl-default-bind-options no-sslv3

defaults
log global
mode tcp
option tcplog
option dontlognull
timeout connect 5000
timeout client 50000
timeout server 50000
errorfile 400 /etc/haproxy/errors/400.http
errorfile 403 /etc/haproxy/errors/403.http
errorfile 408 /etc/haproxy/errors/408.http
errorfile 500 /etc/haproxy/errors/500.http
errorfile 502 /etc/haproxy/errors/502.http
errorfile 503 /etc/haproxy/errors/503.http
errorfile 504 /etc/haproxy/errors/504.http

frontend proxynode
bind *:80
bind *:6443
stats uri /proxystats
default_backend k8sServers

backend k8sServers
balance roundrobin
server master 10.2.0.14:6443 check

listen stats
bind :9999
mode http
stats enable
stats hide-version
stats uri /stats