Why can't I show a field in service desk?

[Antonio Perez Ferrer]

I have a field to choose an insight object and I can't display it, I've tried different ways and I always get the same message. Although I put a pre-established value, it still cannot be displayed, I attach photos so that it can be seen better.

In the black box the text means "This type of field cannot be displayed in the Customer Portal", but as seen in the photo of insight it is configured to appear in the customer portal

https://ibb.co/6m86YKL
https://ibb.co/tzh9R8g
https://ibb.co/gVHnPvC