How can i add the task name/id in the invoices lines

I created the work hours and products out of that task 

want to add the task number to the invoice lines so i can show that number in my invoice report. In the picture i tried to add it only its not coupled with the invoice lines/form and displayes not the right task id/name 


In studio in the app sales and then sales orders i can add the task numbers by dragging a existing block called task_ID. Only this existing block is not availible in accounting