@StephanRS thank you for your question. Unfortunately, this question is difficult to answer without the specific context of your activity template.
Also, Novi is not capable to answers these specific questions yet. It should not have responded in that case. I will tweak the system prompt a little more, that should prevent it from hallucinating.
Is the reason already stored somewhere in the application? Then you can probably access the description of the “reason” with an expression and add that to your export definition as a custom field.
If also if it is a text that can be determined based on a set of conditions, you can try to check for these conditions with “if” statements in a custom expression.
These posts might help: