2D extras error message help

Hello,
I have been attempting to implement the 2D extras pack located at the address https://github.com/Unity-Technologies/2d-extras. But I have run into a particularly disheartening error message that I have no idea how to resolve. The message is as follows:

[[ Failed to resolve packages: The file [C:\Users\ASUS\Unity Game\New Unity Project\Packages\manifest.json] is not a valid JSON: Unexpected token 'c' at 43:4 "com.unity.2d.tilemap.extras": "https://github.com/Unity-Technologies/2d-extra ^. No packages loaded.

A re-import of the project may be required to fix the issue or a manual mondification of C:\Users\ASUS\Unity Game\New Unity Project\Packages\manifest.json file. Click on Retry to relaunch Unity and reopen your project. {{ If this is done, the same error will appear. }} Click on continue to launch Unity. Some or all packages may not be imported which may cause compilation errors. {{ When this is done, Unity loads normally and none of the 2D extras appear to be working. }} ]]

I am using notepad++ to edit the JSON file. I added only the line "com.unity.2d.tilemap.extras": "https://github.com/Unity-Technologies/2d-extras.git#2019.1" to the file. I did install Git and edited it to my user PATH, which admittedly took a long time for me to figure out how to do properly. This pack has been an endless source of frustration for me. My current Unity version is 2019.2.11f1.

Thank you for taking the time to read about my issue.