Problem with bouncing ball ui vertical instead of horinzontal

Question

I was just wondering how I would make this go horizontal or diagonal? right now, it is bouncing vertically would I need to change any of the variables or the pos?

I have tried to change the y to x as well as change the the horizontal width to height but it isn't working can anyone help, mind you I started coding a few weeks ago so i am a little new to everything

from tkinter import *
import time
import tkinter
from turtle import width
tk = Tk()

tk.title("bouncing ball")
tk.resizable(0,0)

canvas_width= 400
canvas_height =500
ball_size = 25
timer_duration = 20

y_move = 2
def draw():
    global y_move
    canvas.move(ball1, 0, y_move)

    pos = canvas.coords(ball1)
    top_y = pos[1]
    bottom_y = pos[2]

    if top_y <= 0:
        y_move = -y_move

    elif bottom_y >= canvas_height:
        y_move = -y_move

def master_timer():
    draw()
    tk.update_idletasks()
    tk.update()
    tk.after(timer_duration, master_timer)

canvas = tkinter.Canvas(tk, width=canvas_width, height=canvas_height, bd=0, highlightthickness= 0)
ball1 = canvas.create_oval(0, 0, ball_size,ball_size,fill="red")
#move ball to center
canvas.move(ball1, canvas_width/2, canvas_width/2)
master_timer()
canvas.pack()
tk.mainloop()