Google AppScript for serving your Sheet as a publicly accessible JSON file. Following these steps in your Google Sheets: https://levelup.gitconnected.com/turn-your-google-sheet-into-a-web-application-f766f1ff8b98

gsheets-get-json.js

function doGet(e) {

  var sheet = SpreadsheetApp.getActiveSheet();

  var range = sheet.getDataRange();
  var values = range.getValues();
  var result = [];

  for (var i = 0; i < values.length; i++) {
    var row = [];
    for (var j = 0; j < values[i].length; j++) {
      if (values[i][j]) {
        row.push(values[i][j]);
      } else {
        row.push('');
      }
    }
    result.push(row);
  }

  return ContentService.createTextOutput(JSON.stringify(result))
    .setMimeType(ContentService.MimeType.JSON);

}