I'm pretty new to writing code and have been playing around with Google Sheets to try to get some basic interaction between some data I have in my sheet and a user interface using HTML. The idea is that I have data in my google sheet that I want to turn into a bar chart in HTML.

In my Sheets I have a column of data that has some values for each month in the format:
July 0
August 32
September 1261
October 0
etc...

In my Code.gs file I have a function that returns this as a list:

//Returns the corresponding yearly waste value for input month. Used for chart.
  function getYearlyWaste() {
    var yearlyWaste = spreadsheet.getRange(2, 28, 12).getValues();
    return yearlyWaste;
  }

When I run this in the Index.html:

google.script.run.withSuccessHandler(wasteVals).getYearlyWaste();

I want to be able to output the getYearlyWaste() function to a variable to use to draw a chart:

function drawChart() {
        var data = google.visualization.arrayToDataTable([
          ['Month', 'Waste', 'Recycling'],
          ['Jan', yearlyWaste[0], yearlyRecycling[0]],
          ['Feb', yearlyWaste[1], yearlyRecycling[1]],
          ['Mar', yearlyWaste[2], yearlyRecycling[2]],
          ['Apr', yearlyWaste[3], yearlyRecycling[3]],
          ['May', yearlyWaste[4], yearlyRecycling[4]],
          ['Jun', yearlyWaste[5], yearlyRecycling[5]],
          ['Jul', yearlyWaste[6], yearlyRecycling[6]],
          ['Aug', yearlyWaste[7], yearlyRecycling[7]],
          ['Sep', yearlyWaste[8], yearlyRecycling[8]],
          ['Oct', yearlyWaste[9], yearlyRecycling[9]],
          ['Nov', yearlyWaste[10], yearlyRecycling[10]],
          ['Dec', yearlyWaste[11], yearlyRecycling[11]]
        ]);

However no matter what I do, I just get undefined. I feel like I'm missing something small, so any help would be appreciated.

As a note, I have tried pulling back individual values from the sheet and assigning them to an element ID value to be sure that the function is working right and I get the expected result.

Thanks in advance :)