Google Sheets API code example in Javascript ES5

I'm having difficulty understanding how to use the Google Sheets API, so for this project, I want to hire someone who has successfully used Google Sheets API before, and provide examples of code and data-structures for me, in Javascript ES5. Note, my Javascript interpreter is ES5, not the ES6 version in current web browsers. Also note: must use XMLHttpRequest for POST'ing to the URL. DO NOT USE AJAX, it is not available in my project. I have an API authorization key you can use, if needed, but it's probably easier for you to create your own Google API credentials and thereby be in control of everything while you are working on it. I need to be able to create 1 spreadsheet. Then I need to be able to add rows, one at a time to the bottom of a collection of values, each row will have about 4 values to put into columns. Lets say the data is 2 integer numbers and 2 dates. I need a SUM() of each column of integers, an AVERAGE() of each column of integers, a COUNT() of each column of integers. I need to be able to open a web browser, navigate myself to Google Sheets, open up this spreadsheet, and look at it. I don't even know how to do that, from having a spreadsheet ID, I dont' know how to open that kind of spreadsheet and look at it. To be awarded this project, tell me in your response, that you have used Google Sheets API, have coded Javascript, know ES5 version, know how to use XMLHttpRequest. If you don't mention these things, you won't get the project awarded.