I can't use Ctrl+Alt+Click to add a vector vertex when I enable "Emulate 3 Button Mouse"

[pendave]

Hi, I use tablet to draw curves and grease pencil in Blender 2.93.

I can't use Ctrl+Alt+Click to add a vector vertex when I enable "Emulate 3 Button Mouse".

How can I set other hot button for this?

Thanks.