I have 3 tabs but I would like to add a 4th tab but I'm not sure how to do it

You have to know how to edit your config settings in json.

Where it says Second Tab and Third Tab, exaime those sections as you will have to create the 4th Tab by simply copying the Thrid Tab section in its entirely to create the 4th tab or any addtional ones.

Merged post

Example:

{
      "ButtonText": "Third Tab",
      "HeaderText": "Third Tab",
      "Pages": [
        {
          "TextLines": [
            "This is third tab, first page.",
            "Add some text here by adding more lines.",
            "You should replace all default text lines with whatever you feel up to",
            "type  /info  to open this window",
            "You may add more pages in config file."
          ],
          "ImageSettings": []
        }
      ],
      "TabButtonAnchor": 4,
      "TabButtonFontSize": 16,
      "HeaderAnchor": 0,
      "HeaderFontSize": 32,
      "TextFontSize": 16,
      "TextAnchor": 3,
      "OxideGroup": ""
    }​

would look like this

{
      "ButtonText": "Third Tab",
      "HeaderText": "Third Tab",
      "Pages": [
        {
          "TextLines": [
            "This is third tab, first page.",
            "Add some text here by adding more lines.",
            "You should replace all default text lines with whatever you feel up to",
            "type  /info  to open this window",
            "You may add more pages in config file."
          ],
          "ImageSettings": []
        }
      ],
      "TabButtonAnchor": 4,
      "TabButtonFontSize": 16,
      "HeaderAnchor": 0,
      "HeaderFontSize": 32,
      "TextFontSize": 16,
      "TextAnchor": 3,
      "OxideGroup": ""
    },
{
      "ButtonText": "Fourth Tab",
      "HeaderText": "Fourth Tab",
      "Pages": [
        {
          "TextLines": [
            "This is fouth tab, first page.",
            "Add some text here by adding more lines.",
            "You should replace all default text lines with whatever you feel up to",
            "type  /info  to open this window",
            "You may add more pages in config file."
          ],
          "ImageSettings": []
        }
      ],
      "TabButtonAnchor": 4,
      "TabButtonFontSize": 16,
      "HeaderAnchor": 0,
      "HeaderFontSize": 32,
      "TextFontSize": 16,
      "TextAnchor": 3,
      "OxideGroup": ""
    }

Thank you, I appreciate the fast response.