PlainText

{
    "fields": [{
        "group": "Default",
        "name": "Plain Text",
        "handle": "plainText", // This line is optional
        "instructions": "This is not a required field.",
        "type": "PlainText",
        // typesettings & everything inside is optional
        "typesettings": {
            "placeholder": "",
            "maxLength": 30,
            "multiline": false // Allow line breaks
        }
    }]
}