How to hang a frame with a sawtooth hanger from a wall?

This might be a 2 part question so I can break it out into two parts if needed.

1. How do I hang a frame with a sawtooth hanger onto a wall with a nail?
2. Can I use a screw and anchor on the wall to hang the frame?

We got a framed picture as a gift and the frame had a sawtooth hanger installed on it. I bought a picture hanging kit but after hammering some picture hooks into the wall, it seems like hooks are not the way to hang frames with a sawtooth hanger.

After doing some research on google, one webpage said I’m supposed to use a flat head nail to hang the frame on. However, I’m having some trouble visualizing how to do it because the instructions on the page said to hammer it in at a 45 degree angle. If I do that, I can’t see how the frame can sit on the nail head since the nail head is at an angle but the sawtooth hanger is flush with the frame.

I was thinking of putting a screw and drywall anchor into the wall for the hanger to sit on but from searching online, I haven’t found anyone suggesting this so my idea might be a stupid one.

So back to my original questions, what is the proper way to hang a frame with a sawtooth hanger, do it with a nail in the wall or do it with a screw and anchor?