Hello @aaaaargzombies and welcome to the Cloudron Forum
I have to apologize.
The tutorial repository is very much out of date.
If you pull the repo again and checkout the branch fix/build it should work.
When the fix/build branch was already merged https://git.cloudron.io/docs/tutorial-typescript-app/-/merge_requests/1 you can simply pull the master branch and it should work.
