You are assigning (i.e. num = 0) instead of using a conditional (i.e. if (someBool === true) {/* Do stuff */}).

Your toggle code should look something like so:

// Easiest way to toggle any value used as a boolean
self.state = !self.state;

// Or if you still want this as an if statement
if (self.state) {
  self.state = 0;
} else {
  // We use an else statement since there can only be two possible values
  self.state = 1;
}

You are assigning (i.e. num = 0) instead of using a conditional (i.e. if (someBool === true) {/* Do stuff */}).

Your toggle code should look something like so:

// Easiest way to toggle any value used as a boolean
self.state = !self.state;

// Or if you still want this as an if statement
if (self.state) {
  self.state = 0;
} else {
  // We use an else statement since there can only be two possible values
  self.state = 1;
}

UPDATE: Remove the keydown event.

I just noticed that you have both a keyup and keydown event listener. Only the keyup event should be on since you want the player to press the key to toggle and then press the toggle key again