How get active person responsible field in T-CODE IW31? Module (PM)

Hello all,

I have created a new class of maintenance orders (ZP51) and I already have created maintenance orders so far without problems using this new order class (ZP51), but i have one problem, the problema is that the new order type does not allow me to enter the person responsible, contrary to the order type (ZP11) which allows me to enter the person responsable successfully, see picture below:

T-CODE IW31:

I have tried to activate this field in the customizing t-CODE SPRO, But I can not find a solution.

How I can activate the person responsible field for T-CODE IW31 ?

Thanks a lot for your time.