Unable to find app.jar

[knjk04]

Describe the bug

When running the backend with Docker, I get 'Error: unable to access jarfile app.jar'

To Reproduce
Steps to reproduce the behaviour:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behaviour

It should be able to find the app jar file (book-app).

Additional context

Error: https://gist.github.com/knjk04/9bb26824e6c2e9af98bc77ac7b88d283

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Add any other context about the problem here (e.g. stack trace, branch name, commit hash, etc.).

[knjk04]

Blocked by #893