I'm trying to make my first sound mod, and I get manifest errors even though the manifest is from the GitHub page.

Code:

{
    "name": "Android UI Mod test",
    "description": "This is just a test.",
    "developer":
    {
        "name": "SoundCrafterYT"
    },
    "icons":
    {
        "512": "icon_512.png"
    },
    "manifest_version": 3,
    "mod":
    {
        "license": "license.txt",
        "payload":
        {
            "keyboard_sounds":
            {
                "TYPING_BACKSPACE":
                [
                    "keyboard/backspace.ogg"
                ]
                "TYPING_ENTER":
                [
                    "keyboard/enter.ogg"
                ]
                "TYPING_LETTER":
                [
                    "keyboard/letter.ogg"
                ]
                "TYPING_SPACE":
                [
                    "keyboard/space.ogg"
                ],
            },
        },
        "schema_version": 1
    },
    "version": "1.0"
}

Error: Manifest is not valid JSON. Line: 24, column: 17, Syntax error.