@MaxonL16591286 open the case type pyDefault rule and go to Advanced Tab and enable the temporary case check box. But pega not recommending the temporary case future from 8.6 and above version.
“You can only create a temporary case for case types without the default Create stage. Case types that you create in Pega Platform 8.5 and later have the Create stage included by default. You can only create a temporary case for case types that you migrate from Pega Platform 8.4 or earlier. For more information, see The Create stage.”