Error:Microsoft.SharePoint.Client.ServerException: Argument SiteUrl must be a tenant administration

Hi: Since I am using on Premises: Below 2 PS commands I have used.

Script1:

#

# Enable the remote site collection creation for on-prem in web application level

# If this is not done, unknon object exception is raised by the CSOM code

#

$WebApplicationUrl = http://dev.contoso.com

$snapin = Get-PSSnapin | Where-Object {$_.Name -eq 'Microsoft.SharePoint.Powershell'}

if ($snapin -eq $null) 

{

    Write-Host "Loading SharePoint Powershell Snapin"

    Add-PSSnapin "Microsoft.SharePoint.Powershell"

}    

$webapp=Get-SPWebApplication $WebApplicationUrl

$newProxyLibrary = New-Object "Microsoft.SharePoint.Administration.SPClientCallableProxyLibrary"

$newProxyLibrary.AssemblyName = "Microsoft.Online.SharePoint.Dedicated.TenantAdmin.ServerStub, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c"

$newProxyLibrary.SupportAppAuthentication = $true

$webapp.ClientCallableSettings.ProxyLibraries.Add($newProxyLibrary)

$webapp.Update()

Write-Host "Successfully added TenantAdmin ServerStub to ClientCallableProxyLibrary."

# Reset the memory of the web application

Write-Host "IISReset..."    

Restart-Service W3SVC,WAS -force

Write-Host "IISReset complete on this server, remember other servers in farm as well."    

 Script2:

#

# Set admin site type property to the site collection using PS for any site collection type.

# This is needed to be set for the site collection which is used as the 

# "Connection point" for the CSOM when site collections are created in on-prem

#

$siteColUrl = http://dev.contoso.com

$snapin = Get-PSSnapin | Where-Object {$_.Name -eq 'Microsoft.SharePoint.Powershell'}

if ($snapin -eq $null) 

{

    Write-Host "Loading SharePoint Powershell Snapin"

    Add-PSSnapin "Microsoft.SharePoint.Powershell"

}

$site = get-spsite -Identity $siteColUrl

$site.AdministrationSiteType = [Microsoft.SharePoint.SPAdministrationSiteType]::TenantAdministration

Still getting error after running the batch file..

[Error] Error during stage "SiteCreation" siteprovisioning: "https://SSSS"
Microsoft.SharePoint.Client.ServerException: Argument SiteUrl must be a tenant administration site.