Correct bezier curve. How to implement?

Question

Canvas

Hello!
There is such a graph:

I decided to try to make it with canvas:
https://codepen.io/CitizenOne/pen/xNMbzE?editors=1010
Question:
How to make a "smooth" line between points. I just get a straight line.
I suppose that you need to make some intermediate points, but I can not figure out how to do it.
Thanks in advance to everyone who helps!

Answer 1

You need to change the coordinates of the control points