Go to the BP_SmartAIComponent then create a new variable called AttackTraceChannel and set its variable type to ETraceTypeQuery then set its default value to Weapon it should look like the image below.

Then create a new variable called CoverTraceChannel and set its variable type to ETraceTypeQuery then set its default value to Cover it should look like the image below.

Next add the highlighted nodes shown in the images below, locations at the tops of the screenshots.