Maybe you tried to upload files, create new content type, or are using SQLite when your app is deployed on Heroku instance.
But it's not possible!
As you maybe don't know, you can't create or update files on Heroku instances. Check the Ephemeral filesystem of Heroku.
File Upload
By default, your local server is set to upload files. Strapi offer you different upload providers you can install and use in your project like AWS S3 buckets or Cloudinary.
Find documentation about this here.
Content Type Builder
The Content Type Builder plugin automatically create multiple files in your /api folder. So it's not match with the storage system of Heroku.
You have to create them on your local machine and then deploy your app on Heroku.
Settings Manager
Exactly the same process as the Content Type Builder. This plugin update all your /config folders, and Heroku don't let you update files.
So you have to made your update in your local machine and then deploy it on Heroku instance.
⚠️ But there is some exceptions
These following configs are set in the database so you can update it when you are in your Strapi app on Heroku:
- The Content Manager UI configs
- Users & Permission configs
- Upload configs
- Email configs