The command
SCONNECTOR enables/disables the OSNAP CONNECTOR
The command can be accessed in the Object Snap context menu (shift + right mouse button), just like for the ENDPOINT:

Its appearance is like this:

When you are When launching the network, as the insertion point of the structure approaches the initial or final point of the tube, the program shows that it can connect:

Note that the icon appears
indicating that the devices will be connected if the point is clicked
All the device connectors also appear, which can be in the color:
If you bring the linear device close and capture the osnap connector, it will be stretched to the connector
Connectors appear on devices whose modeler implements the
Connector tool