location of outlook.com notes on web and creating sub-folder of "Notes" folder

Question

I have been storing notes using the Notes app of iPhone (iOS17) on an Outlook.com account configured on the iPhone,

It seems these notes are stored in the "Notes" folder on the outlook.com mail account on the web. The notes that are added/ entered in a folder named "Notes" on the iPhone do get stored on the outlook account. But if there is another folder other than the "Notes" folder on the outlook account on the iPhone, then the notes stored in that folder are not showing up on the outlook.com web (either as a sub folder of “Notes” folder or elsewhere). Neither is the folder containing those notes showing up on the outlook.com.

I have tried to create sub-folders within the "Notes" folder on the outlook.com web, but those sub-folders become sub-folders only for mails. The option for Notes disappears when such sub-folders are selected.

Queries:

Where do those notes stored in the other folder than "Notes" folder on iPhone disappear on the outlook.com. Are they not stored at all on the outlook.com?

I wish to have sub folders within the "Notes" folder on the outlook.com, similar to the sub-folders used on the iPhone Notes app for Outlook account.