Can not checkout code via ssh-key in windows when self-hosted runner config by unattended

[BondLi1]

When I use ./config.cmd --name $runner_name --unattended --replace --runasservice --url https://github.com/$owner/$project/ --labels $Labels --token $RegistrationToken to setup a self-hosted runner, then let a job run in the runner, then checkout action will fail,

  - name: Code checkout
    uses: actions/checkout@v2
    with:
      ssh-key: ${{ secrets.ssh_private_key }}

I know use unattended in config, then runner will run as network service account, when run as network service account,, checkout action will fail, if run as other account, then will be OK