how can I program the question that the number of selected checkboxes per column and row does not matter? The question contains the product categories bicycle and e-bike. The respondent should now select which categories he is interested in. The number of checks and in which column he sets the check is up to him.
By default, a checkbox question allows respondents to select as many checkboxes as they need/want so you should not need to do anything beyond that.
Unless I don’t understand correctly, your example question should allow respondents to check as many boxes as needed.
Hope this helps!