To add jump blocks:
Right-click on the output port of a block you want to send to another section of the algorithm, and select Add jump block from the menu that appears.
The anchor jump block (green arrow) is attached to the selected output port.
Right-click on the anchor jump block (green arrow) and select Copy from the context menu.
Right-click once more elsewhere on the canvas and select Paste to place the receiving end of the jump block (pink arrow).
Connect the output port of the pasted jump block to the input port of another block.