Need help to avoid colliding with enemies when dashing!!

Sorry about the image, but as you can see, I tried to turn the ‘isTrigger’ on through the BoxCollider2D but it doesn’t work and gives me a NullException Error.
The character dashes just fine but collides with the enemies. I wonder if there is a better way to suspend collisions when dashing?

turn on Trigger is good solution, but i can’t find a line in your script that “BoxCollider bc” connect with something.