You can do this by using the Line tool in the Key Editor.
Or you can do this by using the Drum Stick tool in the Drum Editor.
Or you can draw one long line. Then select the Split tool, hold down Alt/Opt modifier, and split the long note on the left side by the length, you want to use. The split is going to be done multiple times for the whole MIDI Note length.
You can also add one short MIDI Note and use the Repeat Event Ctrl/Cmd + K, where you type, how many times, you want to repeat the event.