Fixed height can be assigned to any row via pq_ht property of row data.
pq_ht works only when rows don't auto expand according to their content i.e., when autoRow option is false
To make pq_ht work irrespective of autoRow value, another property of row data pq_htfix should be set to true
Row heights are changed by dragging the bottom edge of number cells with mouse / pointer device.
Double click on number cell bottom edge resets corresponding row height to auto i.e., row height is adjusted according to its content
To disable change of row heights via UI, set rowResize option to false