1.開發者註冊
先至 https://developers.line.biz/ 註冊
建立一個message api
紀錄channel id/channel secret/channel secret token

2.官方帳號基礎設定
至https://manager.line.biz/ 登入
可以設置官方line基本設定，同時電腦可以預先下載line bot designer
手機下載line official account 登入官方line帳號後 line bot designer

3.安裝line bot sdk
CMD:
pip install line-bot-sdk==1.18.0

4.載入套件
app.py

"""
from flask import Flask, jsonify, request, abort, render_template, redirect, url_for
from flask_cors import CORS
import requests

import os
from dotenv import load_dotenv

from linebot import LineBotApi, WebhookHandler
from linebot.exceptions import LineBotApiError, InvalidSignatureError
from linebot.models import MessageEvent,TextMessage, TextSendMessage
"""

5.建立路由物件

# 載入環境變數
load_dotenv()

app = Flask(__name__, static_folder='templates/assets', static_url_path='/assets')
CORS(app)  # 允許跨域請求

@app.route('/')
def index():
    return redirect(url_for('manage'))

@app.route('/manage')
def manage():
    """首頁路由"""
    return render_template('manage.html')

6.載入環境變數
cmd:

cd <切換至項目根目錄>
pip install python-dotenv
cat > .env << EOF
LINE_CHANNEL_ACCESS_TOKEN="實際的Channel Access Token"
LINE_CHANNEL_SECRET="實際的Channel Secret"
EOF
cat .env

參考相關網址:
https://developers.line.biz/zh-hant/services/messaging-api/