Developer can't select a person from Approver custom field

[Pedro_Gutiérrez]

I have added a new Approver Person on the Incidence info, but the developers can't select the correct Approver because of permissions or something like that

[Earl McCutcheon]

He Pedro,

I believe this is going to be related to the customer permissions on the service desk project. 

Under the Project settings go to "Customer Permissions" and under the section "Who can customers share requests with?"  set this to the value "Any customer or organization, by searching this project. This option allows them to search all customers in the current project."

This option will allow your customers to search for approvers.

Let me know how it goes.

Regards,
Earl