How can I make one-way arrow?

Hi.

I can’t switch the arrow styles.
How can I make one-way style?

You’ll need to edit the note that you want the arrow to point to, and edit the comments to delete the linked note. The arrow will then become one-way.

Jun,

Thank you for your answer.
But I can’t solve the problem still yet, though I tried so.

Is that one what you noticed?
It doesn’t work now, somehow.

For the note you want the arrow to point to:

Click the edit note button

Then the Edit comments button to delete the linked comment:

That will get rid of the arrow pointing backwards.

OMG、I got it !!!
Finally I got what I want to do !!

Thank you so much, Jun !!!