Hi
I have migrated my website today from Heroku to fly. The migration was working well. I have shutdown heroku app, but when I change a variable (secret) on heroku side, it is also changed on fly. why that? Is there any sync between?
There is! When you run through Turboku we setup a webhook to keep your Fly.io app secrets updated. You can disconnect it by removing the Heroku webhook.
Note that if you’re using Heroku Postgres, we need this webhook to keep the DATABASE_URL up to date. Heroku likes to change those without much warning.
Thanks for that, how do I disconnect this webhook?
The application is using a mongodb which is hosted on atlas.
Can I host my app on fly.io without having anything on heroku?
Yes, just remove the webhook from the Heroku control panel.
You can also deploy your app directly and skip the Turboku integration: Speedrun! Deploying to Fly! · Fly Docs
Where is this webhook? I can not see that in heroku settings at all
A friend of mine has deleted the whole heroku app and now it is no more updating, it seems the secrets are no more valid
I’m not sure, you may need to use the Heroku CLI: App Webhooks | Heroku Dev Center
I found it to remove the webhooks, thanks for that
But there is no more connection to heroku after the migration, right?
Heroku can be completly deleted after migration?
If you don’t have a database that lives on Heroku you should be good to go after stopping the webhook 
If you do have a database you’d have to bring it over here or on another database service and connect to your Fly app