REST Adapter, optional parameters

Hi,

I have a rest adapter scenario.  We have the interface with 5 GET operations, one of them sends 2 parameters.  How can I configure that the second parameter is optional? because if I do the next configuration, I get an error when I send the request of an operation with one parameter.  We have PI 7.4 SP 11 and we don't see the "optional" checkbox.

Thanks in advance.