Each time you are storing, if you use the same key, you are overwriting what was there before.
If you want to append, you need to
extract the record using the key
add the new note (append to the list)
store the updated list back using the same key
The downside is that you need to extract a larger and larger list each time you need to add to it.
A more satisfactory approach would be to use new key each time.
And to have an absolute counter.
Basically, you have a record called “last” (key= “last”), which is initially set to 0.
When you save the note, and assuming you want to use “meow” as key, then instead you use “meow_1” because the value of “last” is 0. You increment “last” by 1, and save it using its key, then append the _1 to the key and use THAT augmented key (“meow_1”) to store the first record.
Next time something needs to be added, you do not need to recover all the previous notes (unless you need to display them) just to add a new one. You get “last” out, check its value (say it is “n”) , know that you therefore have “n” records, and that the next one needs to be save using key = “meow_” + (n+1).
You have all the flexibility (if you need to recover all the past notes, you simply need to run the suffix of the index in a repeat loop to create all the keys) and adding new ones does not require you to get them all out each time, so you gain in performance.