The function jr_sum_subtable_column, which is normally used to calculate sums in subtables, cannot be used in the JobRouter app.
Therefore, you have to use other JavaScript functions.
Code examples for the app
var sumperDay = 0;
var sumTotal = 0;
var rowIds = jr_get_subtable_row_ids('stv_untertabelle');
for (var i = 0; i < rowIds.length; i++) {
var rowId = rowIds[i];
sumperDay = jr_get_subtable_value('stv_untertabelle', rowId, 'stv_DayCosts');
sumTotal = parseFloat(sumTotal) + parseFloat(sumperDay);
}