Yes, Potato23 that link wored.
Here's a fix for you.
I added comments to the event sheet to show you what I was doing. Firstly, I had to fix your right-facing image points. Did you know you can right-click on an image point in the image editor and apply it to the whole animation? That way, the cannonballs spawn correctly. I also set your animations to loop (it comes up on the left side of the screen in the image editor), so just change it back over there if that's not what you wanted.
Anyways, I added a private variable to your ship so the game keeps track of which way it's facing. I made sub-events to yours that change the bullet angle of motion for your cannonballs based on the direction of the ship. Remember, 0 degrees is → and it rotates clockwise from there.
Lastly, I moved your firing actions to functions so you can use the same actions for all of your events. This makes it easier to maintain stuff and not copy+paste a bunch of stuff.