Send Slack Message from PowerShell

Send-SlackMessage.ps1

function Send-SlackMessage {
    # Add the "Incoming WebHooks" integration to get started: https://slack.com/apps/A0F7XDUAZ-incoming-webhooks
    param (
        [Parameter(Mandatory=$true, Position=0)]$Text,
        $Url="https://hooks.slack.com/services/xxxxx", #Put your URL here so you don't have to specify it every time.
        # Parameters below are optional and will fall back to the default setting for the webhook.
        $Username, # Username to send from.
        $Channel, # Channel to post message. Can be in the format "@username" or "#channel"
        $Emoji, # Example: ":bangbang:".
        $IconUrl # Url for an icon to use.
    )
    
    $body = @{ text=$Text; channel=$Channel; username=$Username; icon_emoji=$Emoji; icon_url=$IconUrl } | ConvertTo-Json
    Invoke-WebRequest -Method Post -Uri $Url -Body $body
}

Thanks for sharing, been using a while
Recently discovered Rocket.chat as alternative to slack which is 'supposed' to work where you can just replace the webhooks ...etc This works in other apps but have issues w/ this script where the body doesnt get sent and the channel doesn't override the default channel of the webhook? Any ideas by chance?