Flutter Tutorial - HTTP Requests and REST API (GET, POST, PUT and DELETE)

I have some question about delete button, it shows me "type Null is not a subtype of type int" when I click it. Why?

u should make a video how to use factory constructor for fetching rest api

Hey sir plz i want u to answer my question I'm learning flutter but I'm scared cuz OF AI is still opportunities to work as freelancer is still a demand in freelance or i should stop learning flutter