Drawing modular multiplication circle using turtle

I want to draw a modular multiplication circle using turtle library as showed in this link: https://yashaslokesh.github.io/mod-mult-circle.html

My questions are:

1. If the line already drawn, the turtle must not be passed by it again. So how to track the lines and how to do it?

2. If the multiplicator is decimal, how to make the problem work? Since I have seen an animation like this: https://www.youtube.com/watch?v=qhbuKbxJsk8 from 12min17s

Here is my code:

import turtle
import math

pen = turtle.Turtle()
pen.speed(0)

#num = nb of points on the circle
def Points(num, radius):
    points = []
    for i in range(num):
        x = radius*math.cos(i*2*math.pi/num)
        y = radius*math.sin(i*2*math.pi/num)
        #coord = coordonnees des points
        coord = (x,y)
        points.append(coord)
    return points

pointsList = Points(200, 250)

#points = list of the coordinates of points on the circle
def drawPoints(turtle, points):
  turtle.up()
  for i in range(len(points)):
    coord = points[i]
    turtle.goto(coord[0], coord[1])
    turtle.dot(2.5)

def drawLines(turtle, points, mult):
  position = turtle.pos()
  num = len(points) #mod
  for i in range(0,num):
    rem = (i*mult) % num
    start = points[i]
    end = points[rem]
    turtle.penup()
    turtle.goto(start)
    turtle.pendown()
    turtle.goto(end)

drawLines(pen, points, 2)

increment = []
for i in range(1001):
  increment.append(i/10.0)

for i in increment:
  pen.color(255-10*i, 10*i+100, 15*i)
  drawLines(pen, listePoints, i)
  pen.clear()

source https://stackoverflow.com/questions/67762493/drawing-modular-multiplication-circle-using-turtle