Edit field with formula set

[digitalassets]

I have a field that contains an initial (select) formula, but not all rows have information, how can I edit the field if a result does not exist?

Example:

With result:

without result:

the field is hidden

[AleksiAlkio]

Instead of using app formula, you need to use an initial value so you would be able to modify it.

[digitalassets]

Thanks, the initial value accompanied by the input formula allows the objective