Create a boolean variable bCanWallJump.
IN the Hit event, set bCanWallJump to true, and also Set Timer by Event (set it to 3 seconds).ALSO store a reference to this Timer in another variable WallJumpTimer.
Connect the red pin of the Set Timer node to a Custom Event, and on that event’s execution, set bCanWallJump to false.
When player hits the jump button then check the bCanWallJump variable. If it is true, make the pawn wall jump. If it is false, don’t.
When the player wall jumps or lands on the ground or anything else like that, then set bCanWallJump to false AND use that WallJumpTimer variable to stop, reset, and/or invalidate the timer so the player can’t wall jump when they’re not on a wall.