# Why can't I access my environment variables at build time when building from a Dockerfile on App Platform?

If you are using a Dockerfile to deploy your app on App Platform, [environment variables](https://docs.digitalocean.com/products/app-platform/how-to/use-environment-variables/index.html.md) are only available at build time if you have set them using the `--build-arg` [option in Docker](https://docs.docker.com/engine/reference/commandline/build/#build-arg) before deploying the app.

For example, to access the variable `EXAMPLE=your-value` during build time, set it in the image using the `docker` CLI like this:

```shell
docker build --build-arg EXAMPLE=your-value
```

You cannot use this method to access [bindable variables](https://docs.digitalocean.com/products/app-platform/how-to/use-environment-variables/index.html.md#using-bindable-variables-within-environment-variables) at build time. If you are supplying a Dockerfile, bindable variables are only available at runtime.

## Related Topics

[How do I fix the error "Record is managed by an App on this account, and cannot be deleted"?](https://docs.digitalocean.com/support/how-do-i-fix-the-error-record-is-managed-by-an-app-on-this-account-and-cannot-be-deleted/index.html.md): Use the app’s Settings tab to remove domains associated with App Platform apps.

[Why do I get the error “JavaScript heap out of memory” during deployment?](https://docs.digitalocean.com/support/why-do-i-get-the-error-javascript-heap-out-of-memory-during-deployment/index.html.md): Increase the heap memory by setting the environment variable NODE\_OPTIONS=–max-old-space-size=4096.

[How do I fix a "permission denied for schema public" error in my dev database?](https://docs.digitalocean.com/support/how-do-i-fix-a-permission-denied-for-schema-public-error-in-my-dev-database/index.html.md): Delete the existing dev database and create a new one. Then make sure that the app deployment completes successfully.