https://hacksbyme.net/2019/11/14/deployments-to-dxc-s-using-api-with-octopus-deploy/

DeployFromSourceStep2.ps1

# DXC-S deploy from source environment to target environment. Step two, finish the deploy by swapping slots.

if (-not (Get-Module -Name EpiCloud -ListAvailable)) {
    Install-Module EpiCloud -Scope CurrentUser -Force
    Write-Host "Installed EpiCloud module."
}

Connect-EpiCloud -ClientKey $OctopusParameters["DXC-S API Key"] -ClientSecret $OctopusParameters["DXC-S API Secret"]

# Find a deployment that has the status "AwaitingVerification".
$deployments = Get-EpiDeployment -ProjectId $OctopusParameters["DXC-S Project Id"]
$ongoingdeployid = 0
Foreach ($deployment in $deployments) {
    if ($deployment.parameters.targetEnvironment -eq $OctopusParameters["DXC-S Target environment"] ) {
    	if ($deployment.status -eq 'AwaitingVerification') {
          $ongoingdeployid = $deployment.id
          break
      	}
    }
}

if ($ongoingdeployid -eq 0) {
	Write-Error "No deployment with status 'AwaitingVerification' was found." 
}
else {
	Complete-EpiDeployment -ProjectId $OctopusParameters["DXC-S Project Id"] -Id $ongoingdeployid -Wait
}