app.py

from flask import Flask, request, redirect
from utils import verify

app = Flask(__name__)

@app.route('/')
def main():
    if verify(request.args.to_dict()) == request.args.get('hash'):
        return f"Hey {request.args.get('first_name')}!"
    else:
        return "Sorry, You didn't clicked the Auth Button and just redirected here."

if __name__ == '__main__':
    app.run()

utils.py

import hashlib
import hmac

BOT_TOKEN = '1797603327:AAFFCpZIU1pvq4-hL5pmgX4IJR7LtLL9xfU'

def verify(request_data):
    request_data = request_data.copy()
    request_data.pop('hash', None)
    request_data_alphabetical_order = sorted(request_data.items(), key=lambda x: x[0])
    data_check_string = []
    for data_pair in request_data_alphabetical_order:
        key, value = data_pair[0], data_pair[1]
        data_check_string.append(f"{key}={value}")
    data_check_string = '\n'.join(data_check_string)
    secret_key = hashlib.sha256(BOT_TOKEN.encode()).digest()
    return hmac.new(secret_key, msg=data_check_string.encode(), digestmod=hashlib.sha256).hexdigest()