Power Query / M. Create a record with a parameterized field name

Hello experts,

I'm looking for a solution to create a record with a custom field name through a function.

I tried to use the following expression for CreateRecord function but it does not work properly.

(fieldName) =>
let
    rec = [fieldName = "some value"]
in
    rec

In a result, it returns a record with a field named fieldName.

But I'm expecting that it returns a record named as the passed parameter in the function - SpecificFieldName.

Is there a way to do it?

Thank you in advance!