What event we use in frappe server side when post/update method is called from mobile app?

Any thought on this.
I have been using on_insert and on_update. But i am really confused what to use and when.

i think, on_insert is not in the doc_event.

check the documentation of Executing Code On Doctype Events.

Also check the Controller Hooks.

yep sorry for my typo, i mean after_insert.

Actually, i want to trigger notifiaction using mobile app. From mobile app, it triggers in particular doctype in web via api. Then it sends notification to mobile devices from web.

but i am getting empty message while receiving notification @NCP