cant see point markers on rviz

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Hi, my aim is to follow a green ball with the camera and show the movements of this ball in the view. To do this, I marked the middle of the ball with a marker, but I can't see it in the rviz. The code or rviz does not give any errors, what could be the problem? I am using ros neotic Thank you

#!/usr/bin/env python3
import rospy
from sensor_msgs.msg import Image
import cv2
import numpy as np
from cv_bridge import CvBridge, CvBridgeError
import sys

from collections import deque
from imutils.video import VideoStream
from visualization_msgs.msg import Marker, MarkerArray
from geometry_msgs.msg import Point

import gc
import argparse
import time
import imutils


def camdet():
    bridge = CvBridge()
    ap = argparse.ArgumentParser()
    ap.add_argument("-v", "--video", help="Path to the (optional) video file")
    ap.add_argument("-b", "--buffer", default=64, type=int, help="max buffer size")
    args = vars(ap.parse_args())

greenLower = (29, 86, 6)
greenUpper = (64, 255, 255)
pts = deque(maxlen=args["buffer"])

if not args.get("video", False):
    vs = VideoStream(src=0).start()
else:
    vs = cv2.VideoCapture(args["video"])

time.sleep(2.0)


while True:
    frame = vs.read()
    frame = frame[1] if args.get("video", False) else frame
    if frame is None:
        break

    frame = imutils.resize(frame, width=600)
    blurred = cv2.GaussianBlur(frame, (11, 11), 0)
    hsv = cv2.cvtColor(blurred, cv2.COLOR_BGR2HSV)

    mask = cv2.inRange(hsv, greenLower, greenUpper)
    mask = cv2.erode(mask, None, iterations=2)
    mask = cv2.dilate(mask, None, iterations=2)

    cnts = cv2.findContours(mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    cnts = imutils.grab_contours(cnts)
    center = None
    v = 0
    if len(cnts) > 0:
        c = max(cnts, key=cv2.contourArea)
        ((x, y), radius) = cv2.minEnclosingCircle(c)


        M = cv2.moments(c)

        center = (int(M['m10']/M['m00']), int(M['m01']/M['m00']))

        if radius > 10:
            cv2.circle(frame, (int(x), int(y)), int(radius), (0, 255, 255), 2)
            cv2.circle(frame, center, 5, (0, 0, 255), -1)
            v += 1
    pts.append(center)


    marker = Marker()
    marker.header.frame_id = "map"
    marker.ns = "marked"
    marker.id = 0
    marker.type = marker.POINTS
    marker.action = marker.ADD
    marker.pose.orientation.w = 1
    points = [0,0]
    for i in  range(v):
        p = Point()
        p.x = int(M['m10']/M['m00'])
        p.y = int(M['m01']/M['m00'])

        points.clear()
        points.append(p)
        marker.points = points
        print(marker.points)

    marker.scale.x = 0.5
    marker.scale.y = 0.5
    marker.color.g = 0.5
    marker.color.a = 1.0
    marker.color.r = 0.5
    marker.color.b = 1.0
    marker.lifetime = rospy.Duration()




    msg = bridge.cv2_to_imgmsg(frame, encoding="bgr8")
    cv2.imshow("Frame", frame)
    rospy.init_node("object_detection",anonymous=True)
    img_pub = rospy.Publisher('webcam/image_raw', Image, queue_size=10)
    rate = rospy.Rate(10)
    img_pub.publish(msg)
    marker_pub = rospy.Publisher("/marker", Marker, queue_size = 100)

    marker_pub.publish(marker)
    key = cv2.waitKey(1) & 0xFF

    if key == ord('q'):
        break

if not args.get("video", False):
    vs.stop()
else:
    vs.release()

cv2.destroyAllWindows()



if __name__ == '__main__':
    try:
        camdet()
    except rospy.ROSInterruptException:
        pass