How can I get back notes deleted

The information that you are looking for exists in this article that you were reviewing earlier 👉 If you're missing notes on your iPhone, iPad, or iPod touch

If the above does not help then read the following:

Recover Deleted Notes

If iCloud is set to ON for Notes and you deleted some Notes then they are gone from iCloud so cannot be retrieved!  If this is the case then it is all over and no need to read further.

 If you do not use iCloud for Notes then you can restore your iPhone from a backup on your iCloud account (if you use iCloud to back up your iPhone). Once you restore then your Notes will only be as current as when the back up was created. Here is 👉 How to restore your iPhone from an iCloud back up.

The other option is to restore your iPhone from a backup that you may have created on your computer. Once again, if you restore your iPhone from a computer back up then your Notes will only be as current as the day and time the backup was created. 

If you have a backup created on your computer and If you choose to restore your iPhone from your iPhone from it then here is how to do it 👉 Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Axel F.