Alright, so the issue is that since your in Japan, your bot is in the continent of Asia, so now the issue is, heroku doesn’t have servers based in Japan, so it simply won’t work.
If you have a VPN, go to the UK or anywhere in Europe, get the cookie, log out the bot, turn off the vpn, change the cookie in the .env file and then try again.
Any VPN will work, however if you go to the Microsoft store there are some VPNs that might help you (that are free). If your on an apple device look for a VPN that’s free or has a free trial.
Perhaps, since I’m in the UK, I can make an account, you choose the password and username, I get the bot into the group and you rank the bot, I give you the cookie and that’s it, however if you forget the password and username then I can’t do anything about that.