How to get this effect on line

[Patryk34571247i7km]

Hi,

I want to achieve effect like this: 

but when i tried to draw this i can only do it white:

when I add fill then this happens:

how to overcome this?

[Bill Silbert]

Make sure that the fill for the arrow is set to None. 

[Monika Gause]

Like this https://youtube.com/shorts/-LuFVet-AoA