Get SailPoint IdentityNow Sources. Associated Blog Post can be found here https://blog.darrenjrobinson.com/managing-sailpoint-identitynow-roles-via-api-and-powershell/

Get Sources.ps1

$RoleSourceName = "my IdentityNow Source"
$SourceList = Invoke-RestMethod -Method Get -Uri "https://$($orgName).api.identitynow.com/cc/api/source/list" -WebSession $IDN    

# Get SourceID for the Auth Source for Suppliers 
if ($SourceList){
    foreach ($source in $SourceList) {
        # SOURCES
        # Which Source for Role Criteria Rules?        
        if ($source.name.Equals($RoleSourceName)){
            $RoleSource = $source.externalId
            write-host -ForegroundColor Blue "ROLE Source:$($source.name) SourceID:$($source.externalId)"
        } else {
            write-host -ForegroundColor yellow "Source:$($source.name) SourceID:$($source.externalId)"
        }
    }
}