Pass input value to service

Hello, I am new to the ionic creator and angular. I want to pass an input value ( in the textbox ) to a service in a file todos.js so that i can fire Firebase command accordingly.

I want a variable so that i can pass it instead of static text like in this ‘jaipur’

todos.js

angular.module(‘todos’, )

.service(‘Todos’, [’$FirebaseArray’,function($FirebaseArray){
var ref = firebase.database().ref().child(‘jaipur’);
var items = $FirebaseArray(ref);
var todos ={
‘items’: items
}

return todos;

}]);