Button ''group by'' not available

I have a question about the reports KoboToolbox can generate. During the pilot phase of my study, it was possible to generate a report in KoboToolbox using the ‘‘group by’’ button, to sort my data on the outcomes of one question (right panel). However, in current questionnaire the button is not available (left panel). Can someone help me to fix this?

Welcome to the community, @ckd99! Could you please check whether your survey question includes any categorical data? If it only contains integer question types, that option may not be available in the system.