Well, first and foremost... if your manager says that you can't use git, it just means that you can't use their git. If you use your own git with a private project, you can get your work done and not worry about it.

However, I'm a bit concerned because this seems like your company has bad practices in general:

1. No git! Clearly, this is a huge no-no for software development.
2. No code reviews. If you're a JR, it seems like the best place to learn.
3. No testing. Nobody expects you to test your work, so they must expect you to write perfect code without a single issue!
4. No project management framework (Jira, Trello, or anything of the sort). The fact that you setup your own board is great.
5. Nobody in your company seems to have an idea of how to build software.

It appears that you're working for a consulting/outsourcing company. You were sold as a much more experienced developer than you actually are.

Honestly, my advice would be to find a different job. It's definitely not easy, but it may be your best chance to get into an environment where you can grow as a developer and not get infected with terrible "development" practices or lack thereof.

Well, first and foremost... if your manager says that you can't use git, it just means that you can't use their git. If you use your own git with a private project, you can get your work done and not worry about it.

Clarification: the fact that nobody cares where you store the code (work laptop or personal laptop) indicates that a personal git would be no worse than your personal laptop. If this was the only issue you had to deal with, then you could take the initiative here. However, it's clear that this is not the only issue.

It seems like your company has terrible practices in general:

1. No git! Clearly, this is a huge no-no for software development.
2. No code reviews. If you're a JR, it seems like the best place to learn.
3. No testing. Nobody expects you to test your work, so they must expect you to write perfect code without a single issue!
4. No project management framework (Jira, Trello, or anything of the sort). The fact that you setup your own board is great.
5. Nobody in your company seems to have an idea of how to build software.

It appears that you're working for a consulting/outsourcing company. You were sold as a much more experienced developer than you actually are.

Honestly, my advice would be to find a different job. It's definitely not easy, but it may be your best chance to get into an environment where you can grow as a developer and not get infected with terrible "development" practices or lack thereof.