Making the Key Entry in a Input Map Type Variable, a Variable and not a fixed value

Hi,

In the cosNewValues, I need to enter the value of the Key as a variable itself.
As you can see in the attachement, the Key is “${field_variable}” so it should be a variable but the different tries I made faileds:

  1. ${field_variable}
  2. “${field_variable}”

And the value is not recognized by Camunda.

Is there an easy way to make Camunda reads the value in the variable field_variable as a Key?

Should I use scripting instead? In that case how should I set it?

Thanks

Duplicate of Key Entry in a Input Map Type Variable, as a Variable and not a fixed value