Still not quite right, it is essential to get the details right when dealing with computers. Look at the docs again and you will see that
data is an array of arrays (one for each series) whereas you just have it as an array. You can fix that by changing the data line near the end from
You don't need the quotes round the attribute name
x: new Date(msg.payload.items[i].blah.blah.S).getTime()
I notice that you have a trailing comma on the end of the
y: line that should not be there.
Hint: to build an array you can use
myArray.push(element) which adds an element to the end of the array, that will simplify your loop.
By the way, if posting code again please copy/paste the text rather than screenshot, it makes life easier at this end as I could have copied bits of your code rather than having to re-type it. To paste code (or exported flows) got to a new line then click the
</> button and paste the code where it indicates.