Starting a PA Flow from a script

I'm following:

Using site designs and Power Automate to track site creation requests | Microsoft Learn

to the letter. And it's not triggering the flow.

#Define the parameters for the branding:
$themeName = "SiteTemplateBrandingFlowv5"
$site_script = @' 
 {
   "$schema": "schema.json",
     "actions": [
        {
           "verb": "triggerFlow",
           "url": "https://prod-105.westeurope.logic.azure.com:443/workflows/a8609dd2abb14c5gac1183be13ef0099/triggers/manual/paths/invoke?api-version=2016-06-01",
           "name": "Record site creation event",
           "parameters": {
           "event": "site creation",
           "product": "SharePoint Online"
         }
      }
     ],
         "bindata": { }, 
    "version": 1
 }
'@

Connect-SPOService -Url "https://mydomain-admin.sharepoint.com" -Credential $credentials

$addSiteScript = Add-SPOSiteScript -Title $themeName -Content $site_script -Description "Communication site which removes data export for modern experience and adds branding."

Write-Host $addSiteScript.Id

Add-SPOSiteDesign -Title $themeName -WebTemplate "68" -SiteScripts $addSiteScript.Id -Description ""

The flow is just not triggering as mentioned, can anyone see something wrong above. I've used 2 different accounts to create the flow.