can not fetch data from asp.net core web api in flutter

i am trying to develop mobile app in flutter as fronted and asp.net core web api for rest api development in ms sql server data base .
i create web api in
asp.net core web api visual studio 2002 and host in my server panel after publishing the api (entity frame work )
https://app.smartdriveservice.com/api/Users
https://app.smartdriveservice.com/api/Users/2

without entities frame work
https://mobile.smartdriveservice.com/api/CRUD/GetAllRegistration

https://mobile.smartdriveservice.com/api/CRUD/GetAllRegistrationById/1

https://mobile.smartdriveservice.com/api/CRUD/UpdateRegistration

https://mobile.smartdriveservice.com/api/CRUD/AddNewRegistration

https://mobile.smartdriveservice.com/api/CRUD/DeleteRegistration/1

all are working properly in post man .. but when I want to run and fetch in flutter for ui design that data can not retrieve .. ..

any one help me to solve my problem sradhanjali.sradha@gmail.com +91-7008182025