I'm a Windows user. I want to start growthbook locally and modify some code myself. How can I start it locally?

We don't officially support Windows for dev environments, but you might be able to get it to work with WSL. We have some instructions here, but they may be incomplete - https://github.com/growthbook/growthbook/blob/main/CONTRIBUTING.md

I have seen this and installed wsl. Is the Getting started part executed in Ubuntu in wsl?

Yes, I think so. None of our development team use Windows, so we can try our best, but might not be able to help debug windows-specific issues you run into.

good thank you. How to start local development and debugging if you use Mac?