Fleet server in Kubernetes

Hi all!
I noticed that Elastic Agent has variables for containerized deployment if I run this command:
./elastic-agent container -h
Can I deploy Fleet Server, for example in the Kubernetes cluster?
I've tried to use these variables with this yaml :

env:
            - name: FLEET_ENROLL
              value: "1"
            - name: FLEET_INSECURE
              value: "1"
            - name: FLEET_URL
              value: "http://URL:8220"
            - name: FLEET_SERVER_SERVICE_TOKEN
              value: "VALUE"
            - name: FLEET_SERVER_POLICY
              value: "856f4eb0-122f-11ec-8308-176e4cb272f3"
            - name: ELASTICSEARCH_HOST
              value: "https://elasticsearch.em-infra.local:9200"
            - name: KIBANA_FLEET_USERNAME
              value: "USERNAME"
            - name: KIBANA_FLEET_PASSWORD
              value: "PASSWORD"
            - name: FLEET_SERVER_ENABLE
              value: "1"
            - name: FLEET_SERVER_INSECURE_HTTP
              value: "0"
            - name: FLEET_SERVER_ELASTICSEARCH 
              valueFrom:
                secretKeyRef:
                  name: elastic-certificate-pem
                  key: "elastic-certificate.pem"
            - name: NODE_NAME
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name

and got this error

Policy selected for enrollment:  MY_POLICY
2021-10-14T13:16:03.420Z	INFO	cmd/enroll_cmd.go:354	Generating self-signed certificate for Fleet Server
2021-10-14T13:16:03.898Z	INFO	cmd/enroll_cmd.go:526	Spawning Elastic Agent daemon as a subprocess to complete bootstrap process.
2021-10-14T13:16:04.085Z	INFO	application/application.go:66	Detecting execution mode
2021-10-14T13:16:04.086Z	INFO	application/application.go:87	Agent is in Fleet Server bootstrap mode
2021-10-14T13:16:04.224Z	INFO	[api]	api/server.go:62	Starting stats endpoint
2021-10-14T13:16:04.224Z	INFO	[api]	api/server.go:64	Metrics endpoint listening on: /usr/share/elastic-agent/state/data/tmp/elastic-agent.sock (configured: unix:///usr/share/elastic-agent/state/data/tmp/elastic-agent.sock)
2021-10-14T13:16:04.224Z	INFO	application/fleet_server_bootstrap.go:124	Agent is starting
2021-10-14T13:16:04.226Z	INFO	application/fleet_server_bootstrap.go:134	Agent is stopped
2021-10-14T13:16:04.228Z	INFO	stateresolver/stateresolver.go:48	New State ID is sxYbVCI3
2021-10-14T13:16:04.228Z	INFO	stateresolver/stateresolver.go:49	Converging state requires execution of 1 step(s)
2021-10-14T13:16:05.174Z	INFO	log/reporter.go:40	2021-10-14T13:16:05Z - message: Application: fleet-server--7.14.0[]: State changed to STARTING: Starting - type: 'STATE' - sub_type: 'STARTING'
2021-10-14T13:16:05.177Z	INFO	stateresolver/stateresolver.go:66	Updating internal state
2021-10-14T13:16:05.924Z	INFO	cmd/enroll_cmd.go:701	Fleet Server - Starting
2021-10-14T13:16:06.211Z	ERROR	status/reporter.go:236	Elastic Agent status changed to: 'error'
2021-10-14T13:16:06.212Z	ERROR	log/reporter.go:36	2021-10-14T13:16:06Z - message: Application: fleet-server--7.14.0[]: State changed to FAILED: Error - x509: certificate signed by unknown authority - type: 'ERROR' - sub_type: 'FAILED'
2021-10-14T13:16:06.926Z	INFO	cmd/enroll_cmd.go:701	Fleet Server - Error - x509: certificate signed by unknown authority
2021-10-14T13:16:12.936Z	INFO	cmd/enroll_cmd.go:706	Fleet Server - Error - x509: certificate signed by unknown authority
2021-10-14T13:16:16.213Z	INFO	status/reporter.go:236	Elastic Agent status changed to: 'online'
2021-10-14T13:16:16.213Z	INFO	log/reporter.go:40	2021-10-14T13:16:16Z - message: Application: fleet-server--7.14.0[]: State changed to RESTARTING:  - type: 'STATE' - sub_type: 'STARTING'
2021-10-14T13:16:16.213Z	INFO	log/reporter.go:40	2021-10-14T13:16:16Z - message: Application: fleet-server--7.14.0[]: State changed to STARTING: Starting - type: 'STATE' - sub_type: 'STARTING'
2021-10-14T13:16:16.213Z	INFO	log/reporter.go:40	2021-10-14T13:16:16Z - message: Application: fleet-server--7.14.0[]: State changed to RESTARTING: Restarting - type: 'STATE' - sub_type: 'STARTING'
2021-10-14T13:16:16.748Z	INFO	log/reporter.go:40	2021-10-14T13:16:16Z - message: Application: fleet-server--7.14.0[]: State changed to STARTING: Starting - type: 'STATE' - sub_type: 'STARTING'
2021-10-14T13:16:16.944Z	INFO	cmd/enroll_cmd.go:701	Fleet Server - Starting
2021-10-14T13:16:17.248Z	ERROR	status/reporter.go:236	Elastic Agent status changed to: 'error'

Maybe anybody has experience with setting up the Elastic Agent with Fleet Server in Kubernetes?

Thank you all!