How to fix AttributeError: 'RegisterModel' object has no attribute 'Users' and 500 Internal Server Error / web.py

Question

I got this Error, I am trying to create a simple web project using web.py. But unfortunately when I try to register a user I got the error. I tried so hard but I can't find any way to solve this. Would anyone please help to find out the solution to my problem? Error:

Traceback (most recent call last):
  File "C:\Users\Fahim\AppData\Local\Programs\Python\Python38\lib\site-packages\web\application.py", line 280, in process
    return self.handle()
  File "C:\Users\Fahim\AppData\Local\Programs\Python\Python38\lib\site-packages\web\application.py", line 271, in handle
    return self._delegate(fn, self.fvars, args)
  File "C:\Users\Fahim\AppData\Local\Programs\Python\Python38\lib\site-packages\web\application.py", line 517, in _delegate
    return handle_class(cls)
  File "C:\Users\Fahim\AppData\Local\Programs\Python\Python38\lib\site-packages\web\application.py", line 495, in handle_class
    return tocall(*args)
  File "F:\Programs\Python\Python 3 Beginner to Advanced\10 Project 5 - Web Development Project Using Web.py\CodeWizard\Controller.py", line 30, in POST
    reg_model.insert_user(data)
  File "F:\Programs\Python\Python 3 Beginner to Advanced\10 Project 5 - Web Development Project Using Web.py\CodeWizard\Models\RegisterModel.py", line 15, in insert_user
    id = self.Users.insert({"username": data.username, "name": data.name, "password": data.password, "email": data.email})
AttributeError: 'RegisterModel' object has no attribute 'Users'
127.0.0.1:13919 - - [28/Nov/2022 01:30:44] "HTTP/1.1 POST /postregistration" - 500 Internal Server Error

Register.html:

<div class="container">
    <h2>Register Account</h2>
    <br/><br/>
    <form id="register-form">

        <div class="form-group has-info label-static is-empty">
            <label for="username" class="control-label">Username</label>
            <input id="username" name="username" class="form-control" type="text" placeholder="Choose a username"/>
        </div>
        <div class="form-group has-info label-static is-empty">
            <label for="display_name" class="control-label">Full Name</label>
            <input id="display_name" name="name" class="form-control" type="text" placeholder="Enter your full name"/>
        </div>
        <div class="form-group has-info label-static is-empty">
            <label for="email" class="control-label">Email Address</label>
            <input id="email" name="email" class="form-control" type="email" placeholder="Enter your email"/>
        </div>
        <div class="form-group has-info label-static is-empty">
            <label for="password" class="control-label">Password</label>
            <input id="password" name="password" class="form-control" type="password" placeholder="Make a password"/>
        </div>

        <button type="submit" class="btn btn-raised btn-info">Submit<div class="ripples-container"></div></button>

    </form>

</div>

code of RegisterModel.py:
import pymongo
from pymongo import MongoClient


class RegisterModel:
    def __int__(self):
        self.client = MongoClient()
        self.db = self.client.codewizard
        self.Users = self.db.users

    def insert_user(self, data):

        id = self.Users.insert({"username": data.username, "name": data.name, "password": data.password, "email": data.email})
        print("uid is", id)