Formula: Variable as object property name is not accepted

While I can POST successfully a document with the body shown in the first picture
→ {fields: {“”: {stringValue: “Admin”}}}

it appears in Firebase:

This does not work, as soon as I try to set the object property name by a variable. The code is not accepted by Composer shows the following message:

Does someone know, how to solve this?

Same here:

A fixed string is accepted (but this is pointless for the use-case):

The variable is not accepted:



added this to the bug tracker:

Finally found a hack to this issue:

  • it is possible to set the object key to a variable by using a cascade of “SET_KEY()” formula-functions.
  • there is still a warning, but now it is a yellow one :slight_smile: ; that means the formula can be saved and executed.