The below example uses online licensing and requests a specific license (both the OrderId and LicenseTypeId must be used):

$lictype = Get-LicenseType -KempId jbloggs@kemptechnologies.com -Password supersecretpassword `
                 -LoadBalancer 172.21.59.85 -Credential bal -OrderId marvel20170511-01
$lictype | Format-List
ReturnCode : 200
Response   : Command successfully executed.
Data       : @{License=System.Object[]}
 
$lic = Request-LicenseOnline -LoadBalancer 172.21.59.85 -Credential bal `
                             -KempId jbloggs@kemptechnologies.com -Password supersecretpassword `
                           -LicenseTypeId $lictype.Data.License[0].id -OrderId marvel20170511-01
$lic | Format-List
ReturnCode : 200
Response   : Command successfully executed.
Data       :