Before starting coding in Xamarin your database must be prepared for connection. First you must grant permission to your user name for database and tables. To grant permission your user name for database please read this and to grant permission your table please use below in your terminal;
GRANT ALL PRIVILEGES ON TABLE people TO admin;
Not: do not forget semicolon if you do not put semicolon your code will not work.
We do not need to do anything in PostgreSQL. Now we can write code in Xamarin let’s start.