部署在Heroku上的Python Discord Bot无响应问题求助

我已成功将Discord Bot部署到Heroku，但机器人仍无法正常工作。该Bot在本地运行完全正常，但部署到Heroku后无法做出任何响应。相关GitHub仓库地址：https://github.com/MidnightSonor/malifaux_discord_bot

运行日志如下：

2022-10-13T12:44:01.000000+00:00 app[api]: Build started by user dashevsky.andry@gmail.com
2022-10-13T12:44:22.188723+00:00 app[api]: Release v18 created by user dashevsky.andry@gmail.com
2022-10-13T12:44:22.188723+00:00 app[api]: Deploy 56113237 by user dashevsky.andry@gmail.com
2022-10-13T12:44:24.832319+00:00 heroku[worker.1]: State changed from crashed to starting
2022-10-13T12:44:26.000000+00:00 app[api]: Build succeeded
2022-10-13T12:44:26.365888+00:00 heroku[worker.1]: Starting process with command `python3 main.py`
2022-10-13T12:44:26.952729+00:00 heroku[worker.1]: State changed from starting to up
2022-10-13T12:44:27.929643+00:00 app[worker.1]: [2022-10-13 12:44:27] [INFO    ] discord.client: logging in using static token
2022-10-13T12:44:28.683273+00:00 app[worker.1]: [2022-10-13 12:44:28] [INFO    ] discord.gateway: Shard ID None has connected to Gateway (Session ID: bf35f7b917978582c1cb6a861dba38eb).
2022-10-13T12:44:30.686669+00:00 app[worker.1]: Malifaux Deck Bot#4754 has connected to Discord!

内容的提问来源于stack exchange，提问作者Andry Dashesky