How do I load the 2D extras into unity(with Git)

the title says it all

If you’ve downloaded from Git, go to your project’s Packages folder are create a folder there called com.unity.2d.tilemap.extras and then move the repo into it.

You can also try editing your manifest to download it into your project.

https://github.com/Unity-Technologies/2d-extras#how-to-use-this