My config.toml file

concurrent = 1
check_interval = 0
shutdown_timeout = 0

[session_server]
  session_timeout = 1800

[[runners]]
  name = "fargate testing"
  url = "https://code.xx.com/"
  id = 2715
  token = "xxxxxxxxxxxxxxx"
  token_obtained_at = 2024-07-18T17:34:41Z
  token_expires_at = 0001-01-01T00:00:00Z
      executor = "custom"
      builds_dir = "/opt/gitlab-runner/builds"
      cache_dir = "/opt/gitlab-runner/cache"
      [runners.custom_build_dir]
      [runners.cache]
        Type = "s3"
        MaxUploadedArchiveSize = 0
        [runners.cache.s3]
          ServerAddress = "s3.amazonaws.com"
          BucketName = "aie-gitlab-runner-cache"
          BucketLocation = "us-east-1"
      [runners.custom]
        config_exec = "/opt/gitlab-runner/fargate"
        config_args = ["--config", "/etc/gitlab-runner/fargate.toml", "custom", "config"]
        prepare_exec = "/opt/gitlab-runner/fargate"
        prepare_args = ["--config", "/etc/gitlab-runner/fargate.toml", "custom", "prepare"]
        run_exec = "/opt/gitlab-runner/fargate"
        run_args = ["--config", "/etc/gitlab-runner/fargate.toml", "custom", "run"]
        cleanup_exec = "/opt/gitlab-runner/fargate"
        cleanup_args = ["--config", "/etc/gitlab-runner/fargate.toml", "custom", "cleanup"]

This is my fargate.toml file

LogLevel = "info"
LogFormat = "text"

[Fargate]
  Cluster = "fargate-cluster"
  Region = "us-east-1"
  Subnet = "subnet-xxxxxxx"
  SecurityGroup = "sg-xxxxx"
  TaskDefinition = "fargate-task"
  EnablePublicIP = false

[TaskMetadata]
  Directory = "/opt/gitlab-runner/metadata"

[SSH]
  Username = "ubuntu"
  Port = 22

when I tried to run the pipeline i am getting this error. I am not sure why the handshake is failing PLease help me.

INFO[2024-07-18T17:43:36Z] [Execute] Will connect to server and execute the specified shell script  PID=23125 command=run_exec stage=prepare_script
INFO[2024-07-18T17:43:36Z] will not retry operation                      PID=23125 
command=run_exec error="connecting to server "172.28.222.139:22" as user "ubuntu":
 ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain" stage=prepare_script
ERRO[2024-07-18T17:43:36Z] Application execution failed                  PID=23125 
error="executing the script on the remote host: executing script on container with IP "172.28.222.145": 
connecting to server: connecting to server "172.28.222.145:22" as user "ubuntu": ssh:
handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain"
ERROR: Job failed (system failure): prepare environment: exit status 2. Check [https://docs.gitlab.com/runner/shells/index.html#shell-profile-loading][1] for more information

The solution mentioned in the below official document is not helping