i would like to Add a point to end node of Lines that has no more connection with any lines or any area .

i have read ,that i have to use vertex creator ,Add point but iam not sure how it works

i have used aggregator group by network_id , so i have many lines connecting together ,depend on the network .

i would like to add a node at end of each network when the network has no lines connecting from any side ,so i want to add the point , but if there is connection between lines and another lines so i do not need to add a point .

somelines have already node at the end without any connection lines but some not ,my target the line that has no node at end ,i want to add a point

Thanks in advance for any help .