KPHAx‖Connect

nCBkq‖Creates a line or Bézier curve by connecting two or more lines, Bézier curves, or other objects with a line. Closed objects containing a fill are converted to lines and lose their fill.

To access this command...

kDQFF‖Choose Shape - Connect (LibreOfficeDev Draw only)

DNEs5‖Select two or more lines, open the context menu and choose Connect.