The Subscription Settings service and corresponding application and proxy needs to be running in order to make changes to these settings.

Error:

The Subscription Settings service and corresponding application and proxy needs to be running in order to make changes to these settings.

Reason:
You will get this error when you are trying to create the "App URL" through "Configure App URLs" in central admin.

Solution:

• First you need to provide the "db creator" role for the specific user which you are going to use for the "Subscription service"
• Then you need to enable the "Subscription service" ONLY  through the below PowerShell script. (Replace your actual values in the highlighted areas)

$account = Get-SPManagedAccount domainname\username
$appPool = New-SPServiceApplicationPool -Name SubscriptionServiceAppPool -Account $account 
$serviceApp = New-SPSubscriptionSettingsServiceApplication -ApplicationPool $appPool -name "Subscription Settings Service Application" -DatabaseName "SP2013DEV-SubscriptionSettingsDB" 
$serviceAppProxy = New-SPSubscriptionSettingsServiceApplicationProxy -ServiceApplication $serviceApp

• Then go to Application management  --> Manage services on the server  and start the "Microsoft SharePoint Foundation Subscription Settings Service" service
• Then click the "Apps" in the left navigation and click the "Configure Apps URLs" and your error will not be displayed there