How do I draw a graph in a loop so that the graph of the previous cycle remains in the drawing? (matplotlib)

I started learning python quite recently, as it is convenient to draw 3D graphics with matplotlib (you need it for a diploma). So far I'm trying to draw a 2d graph, but I have two windows at the end of the program showing no graph (empty axes). Where can there be a mistake? How can I make the loop draw a graph in one window and complement the previous graph?

import numpy as np
import math
from classes import Point
import matplotlib.pyplot as plt
from matplotlib import cm
from mpl_toolkits.mplot3d import axes3d

# Инициализируем данные
eps: float = float(1/100)
h: float = float(0.0001)
t: float = float(30)
a: int = -10
b: int = 10
xmi = -15
ymi = -15
xma = 15
yma = 15
N: int = 0

# Глобальные переменные (массивы)
OTX = [0]*100
OTY = [0]*100
OTZ = [0]*100
X1 = [0]*100
X2 = [0]*100
Y1 = [0]*100
Y2 = [0]*100
Z1 = [0]*100
Z2 = [0]*100

# Объявили функции
def f1(x, y, z, t):
    return ((float)(y - pow(x, 3) / 3.0 + x)) / eps

def f2(x, y, z, t):
    return -x + z

def f3(x, y, z, t):
    return x*y

def f(x):
    return (float)(pow(x, 3) / 3.0 - x)

def rungeKutta():
    i=0
    while i < N:
        OTX[i] = float(input("x{0} = ".format(i + 1)))
        OTY[i] = float(input("y{0} = ".format(i + 1)))
        OTZ[i] = float(input("z{0} = ".format(i + 1)))
        i += 1

    i = 0
    while i < N:
        X1[i] = OTX[i]
        Y1[i] = OTY[i]
        Z1[i] = OTZ[i]
        i += 1

    qX1 = 0
    qX2 = 0
    qX3 = 0
    qY1 = 0
    qY2 = 0
    qY3 = 0
    qZ1 = 0
    qZ2 = 0
    qZ3 = 0
    j: int = 0

    plt.ion()
    while j < N:
        ansX = []
        ansY = []
        ansZ = []

        time = 0
        while time < t:
            if abs(X1[j]) < 10000 and abs(Y1[j]) < 10000:
                qX1 = h * f1(X1[j], Y1[j], Z1[j], time)
                qY1 = h * f3(X1[j], Y1[j], Z1[j], time)
                qZ1 = h * f1(X1[j], Y1[j], Z1[j], time)

                qX2 = h * f1(X1[j] + qX1 / 2, Y1[j] + qY1 / 2, Z1[j] + qZ1 / 2, time + h / 2)
                qY2 = h * f2(X1[j] + qX1 / 2, Y1[j] + qY1 / 2, Z1[j] + qZ1 / 2, time + h / 2)
                qZ2 = h * f3(X1[j] + qX1 / 2, Y1[j] + qY1 / 2, Z1[j] + qZ1 / 2, time + h / 2)

                qX3 = h * f1(X1[j] - qX1 + 2 * qX2, Y1[j] - qY1 + 2 * qY2, Z1[j] - qZ1 + 2 * qZ2, time + h)
                qY3 = h * f2(X1[j] - qX1 + 2 * qX2, Y1[j] - qY1 + 2 * qY2, Z1[j] - qZ1 + 2 * qZ2, time + h)
                qZ3 = h * f3(X1[j] - qX1 + 2 * qX2, Y1[j] - qY1 + 2 * qY2, Z1[j] - qZ1 + 2 * qZ2, time + h)

                X2[j] = X1[j] + (qX1 + 4 * qX2 + qX3) / 6
                Y2[j] = Y1[j] + (qY1 + 4 * qY2 + qY3) / 6
                Z2[j] = Z1[j] + (qZ1 + 4 * qZ2 + qZ3) / 6

            ansX.append(X2[j])
            ansY.append(Y2[j])
            ansZ.append(Z2[j])

            time += h

        j += 1

        plt.plot(ansX, ansY)
        plt.draw()
        plt.pause(0.1)
    plt.ioff()
    plt.show()


# Начало программы
N = int(input("Введите количество точек (N): "))
rungeKutta()

I had other rendering options (already 3d) like this:

 fig = plt.figure()
 ax = fig.add_subplot(111, projection='3d')

 ax.plot_wireframe(X, Y, Z, rstride=8, cstride=8, alpha=0.5)

 ax.set_xlim(-40, 40)
 ax.set_ylim(-40, 40)
 ax.set_zlim(-100, 100)

 ax.set_xlabel('X')
 ax.set_ylabel('Y')
 ax.set_zlabel('Z')


 plt.show()

Where X Y Z is the ansX ansY ansZ from the code higher. But I do not know how to draw again in a loop. Please tell me, I couldn't find anything that worked