Send-MessageCard.ps1

#region MessageCard function helpers
function MessageCard {
    param([scriptblock]$ScriptBlock)

    $newScript = "@{$($ScriptBlock.ToString())}"
    $newScriptBlock = [scriptblock]::Create($newScript)
    & $newScriptBlock
}

function section {
    param([scriptblock]$ScriptBlock)

    $newScript = "[Ordered]@{$($ScriptBlock.ToString())}"
    $newScriptBlock = [scriptblock]::Create($newScript)
    & $newScriptBlock
}

function fact {
    param([scriptblock]$ScriptBlock)

    $Invoked = $ScriptBlock.Invoke() 
    $Invoked.Keys | 
        ForEach-Object {
        
        @{
            Name  = $_
            Value = $Invoked.$_
        }
    }
}
#endregion

#region Main
$NewMessage = MessageCard {
    summary = 'This is the summary property'
    title   = "This is the card's title property"
    text    = 'This is the cards text property.'

    sections = @(

        section { 
            activityTitle = 'Activity Title'
            activitySubtitle = 'Activity **Sub**Title'
            images = @(
                @{
                    image = "http://connectorsdemo.azurewebsites.net/images/WIN12_Scene_01.jpg"
                    title = "This is the image alternate text Pic 01"
                }
        
                @{
                    image = "http://connectorsdemo.azurewebsites.net/images/WIN12_Anthony_02.jpg"
                    title = "This is the image alternate text Pic 02"
                }
            )
            PotentialAction = @(
                @{
                    '@type' = 'Actioncard'
                    Name = 'Comment'
                    Inputs = @(
                        @{
                            '@type' = 'TextInput'
                            Id = 'Comment'
                            isMultiLine = $true
                            Title = 'Input title property'
                        }
                    )
                    Actions = @(
                        @{
                            '@type' = 'HttpPOST'
                            Name = 'Save'
                            Target = 'http://...'
                        }
                    )
                }

                @{
                    '@type' = 'Actioncard'
                    Name = 'Due Date'
                    Inputs = @(
                        @{
                            '@type' = 'DateInput'
                            Id = 'dueDate'
                            Title = 'Input due date'
                        }
                    )
                    Actions = @(
                        @{
                            '@type' = 'HttpPOST'
                            Name = 'Save'
                            Target = 'http://...'
                        }
                    )
                }
            )
        }

        section { 
            title = 'Details:'
            facts = fact {
                @{
                    GivenName = 'Irwin'
                    SurName   = 'Strachan'
                }
            }
        }
        
        section { 
            activityTitle    = 'Default MD Support'
            activitySubtitle = 'Activity **Subtitle**'
            facts = fact {
                @{
                    Email   = 'Irwin@DosSantos.ca'
                    WebSite = '[pshirwins](https://pshirwin.wordpress.com)'
                }
            }
        }
    )
} 

$restparams = @{
    Uri         = "Your WebHook Uri"
    Method      = 'POST'
    Body        = $($NewMessage | ConvertTo-Json -Depth 6)
    ContentType = 'application/JSON'
}

Invoke-RestMethod @restparams
#endregion