When creating a defined property, you might want to map it to an existing property from an integration instead of assigning it a static value.
However, in some cases, this isn’t possible. Here's an example:
Why does "Deal Amount" appear in the first dropdown, but not in the second one?
Defined properties can only map to text fields.
If a property is a number, boolean, or date field, it won’t appear as an option in the second dropdown.